Supporting MERGE on updatable views

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index 3c9459b..114e331
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 0371f51..660a62a
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -768,7 +768,7 @@ CopyFrom(CopyFromState cstate)
 	estate->es_rteperminfos = cstate->rteperminfos;
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 2c2b3a8..df06520
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -985,11 +985,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1013,10 +1015,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1044,6 +1047,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index fce9d63..f39fbe6
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 596b9a1..291fa43
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -169,11 +169,13 @@ static TupleTableSlot *internalGetUpdate
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2639,13 +2641,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2686,9 +2689,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2703,8 +2707,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2725,7 +2731,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2751,22 +2757,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2828,9 +2844,28 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				ExecUpdatePrepareSlot(resultRelInfo, newslot, context->estate);
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, mtstate->canSetTag, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, mtstate->canSetTag,
+										   &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2848,7 +2883,25 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+				}
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3620,7 +3673,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3698,7 +3752,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3731,9 +3786,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3805,7 +3879,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -3981,6 +4056,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4002,7 +4081,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4078,8 +4157,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
new file mode 100644
index 6613992..de3a334
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -7109,7 +7109,6 @@ make_modifytable(PlannerInfo *root, Plan
 			RangeTblEntry *rte = planner_rt_fetch(rti, root);
 
 			Assert(rte->rtekind == RTE_RELATION);
-			Assert(operation != CMD_MERGE);
 			if (rte->relkind == RELKIND_FOREIGN_TABLE)
 				fdwroutine = GetFdwRoutineByRelId(rte->relid);
 			else
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index c2239d1..1cfe7ce
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -186,12 +186,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index f6fc62a..c9e73e6
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -846,8 +846,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 3844f2b..67c2eaa
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 7cf0cea..f286646
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -85,10 +85,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1462,7 +1462,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1470,7 +1470,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1679,11 +1679,12 @@ fill_extraUpdatedCols(RangeTblEntry *tar
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1691,10 +1692,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1703,6 +1700,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1778,9 +1792,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1788,7 +1802,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1798,6 +1813,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2491,11 +2507,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2511,6 +2534,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3052,6 +3103,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3064,6 +3207,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3087,55 +3231,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3161,6 +3299,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3189,6 +3346,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3197,6 +3362,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3260,8 +3449,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3383,7 +3572,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3406,6 +3596,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3498,10 +3714,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3553,11 +3769,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3611,14 +3828,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3893,7 +4109,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3937,7 +4153,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3947,7 +4164,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3959,39 +4177,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 2a07502..038a464
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -474,9 +474,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -485,6 +486,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -660,9 +664,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -671,6 +676,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 2a39219..faee51d
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index a1202a0..8c25c4a
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 34bc640..a38062e
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -160,6 +160,8 @@ typedef struct Query
 
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	bool		mergeUseOuterJoin;	/* whether to use outer join */
+	int			mergeTargetSrcIdx;	/* rtable index of target relation that
+									 * MERGE pulls data from */
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 6c8a18f..26223c8
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 5a47dac..8dd8cde
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,65 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1250,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1267,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1296,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1324,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1352,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1363,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1379,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1389,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1405,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1424,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1437,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1456,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1515,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1547,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1568,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1579,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1608,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1618,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1634,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1663,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1689,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1706,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1730,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1745,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1760,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1780,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1799,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1820,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1845,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1855,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2230,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2291,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2306,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2360,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2656,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2673,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2685,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2707,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3351,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 98fe104..f300c61
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index a6aebbc..1cc8797
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,55 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +554,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +568,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +593,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +612,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +631,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +649,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +666,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +676,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +693,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +703,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +735,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +752,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +769,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +779,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +788,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +806,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +826,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +850,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +869,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +898,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +912,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +948,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +987,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1170,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1214,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1386,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1716,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index 3c9459b..114e331
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 0371f51..660a62a
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -768,7 +768,7 @@ CopyFrom(CopyFromState cstate)
 	estate->es_rteperminfos = cstate->rteperminfos;
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 2c2b3a8..df06520
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -985,11 +985,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1013,10 +1015,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1044,6 +1047,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index fce9d63..f39fbe6
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 596b9a1..291fa43
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -169,11 +169,13 @@ static TupleTableSlot *internalGetUpdate
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2639,13 +2641,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2686,9 +2689,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2703,8 +2707,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2725,7 +2731,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2751,22 +2757,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2828,9 +2844,28 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				ExecUpdatePrepareSlot(resultRelInfo, newslot, context->estate);
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, mtstate->canSetTag, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, mtstate->canSetTag,
+										   &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2848,7 +2883,25 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+				}
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3620,7 +3673,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3698,7 +3752,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3731,9 +3786,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3805,7 +3879,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -3981,6 +4056,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4002,7 +4081,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4078,8 +4157,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
new file mode 100644
index 6613992..de3a334
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -7109,7 +7109,6 @@ make_modifytable(PlannerInfo *root, Plan
 			RangeTblEntry *rte = planner_rt_fetch(rti, root);
 
 			Assert(rte->rtekind == RTE_RELATION);
-			Assert(operation != CMD_MERGE);
 			if (rte->relkind == RELKIND_FOREIGN_TABLE)
 				fdwroutine = GetFdwRoutineByRelId(rte->relid);
 			else
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 4cec12a..b5711b4
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -187,12 +187,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
new file mode 100644
index 137b283..1a4e13e
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -157,15 +157,14 @@ preprocess_targetlist(PlannerInfo *root)
 			/*
 			 * Add resjunk entries for any Vars used in each action's
 			 * targetlist and WHEN condition that belong to relations other
-			 * than target.  Note that aggregates, window functions and
-			 * placeholder vars are not possible anywhere in MERGE's WHEN
-			 * clauses.  (PHVs may be added later, but they don't concern us
-			 * here.)
+			 * than target.  Note that aggregates and window functions are not
+			 * possible anywhere in MERGE's WHEN clauses, but PlaceHolderVars
+			 * may have been added by subquery pullup.
 			 */
 			vars = pull_var_clause((Node *)
 								   list_concat_copy((List *) action->qual,
 													action->targetList),
-								   0);
+								   PVC_INCLUDE_PLACEHOLDERS);
 			foreach(l2, vars)
 			{
 				Var		   *var = (Var *) lfirst(l2);
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index f6fc62a..c9e73e6
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -846,8 +846,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 3844f2b..67c2eaa
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 7cf0cea..f286646
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -85,10 +85,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1462,7 +1462,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1470,7 +1470,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1679,11 +1679,12 @@ fill_extraUpdatedCols(RangeTblEntry *tar
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1691,10 +1692,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1703,6 +1700,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1778,9 +1792,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1788,7 +1802,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1798,6 +1813,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2491,11 +2507,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2511,6 +2534,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3052,6 +3103,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3064,6 +3207,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3087,55 +3231,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3161,6 +3299,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3189,6 +3346,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3197,6 +3362,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3260,8 +3449,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3383,7 +3572,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3406,6 +3596,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3498,10 +3714,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3553,11 +3769,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3611,14 +3828,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3893,7 +4109,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3937,7 +4153,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3947,7 +4164,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3959,39 +4177,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 2a07502..038a464
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -474,9 +474,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -485,6 +486,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -660,9 +664,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -671,6 +676,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 2a39219..faee51d
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index a1202a0..8c25c4a
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 34bc640..a38062e
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -160,6 +160,8 @@ typedef struct Query
 
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	bool		mergeUseOuterJoin;	/* whether to use outer join */
+	int			mergeTargetSrcIdx;	/* rtable index of target relation that
+									 * MERGE pulls data from */
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 6c8a18f..26223c8
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 5a47dac..462ec00
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,84 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- PlaceHolderVar in MERGE WHEN condition
+CREATE OR REPLACE VIEW rw_view2 AS SELECT *, 'xxx' AS c FROM base_tbl;
+CREATE TRIGGER rw_view2_ins_trig INSTEAD OF INSERT ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'r'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND c = 'xxx' THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | r0
+  1 | r1
+  2 | r2
+  3 | r3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1269,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1286,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1315,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1343,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1371,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1382,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1398,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1408,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1424,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1443,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1456,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1475,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1534,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1566,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1587,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1598,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1627,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1637,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1653,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1682,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1708,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1725,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1749,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1764,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1779,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1799,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1818,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1839,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1864,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1874,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2249,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2310,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2325,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2379,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2675,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2692,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2704,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2726,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3370,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 98fe104..f300c61
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index a6aebbc..a341d57
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,65 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- PlaceHolderVar in MERGE WHEN condition
+CREATE OR REPLACE VIEW rw_view2 AS SELECT *, 'xxx' AS c FROM base_tbl;
+CREATE TRIGGER rw_view2_ins_trig INSTEAD OF INSERT ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'r'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND c = 'xxx' THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +564,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +578,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +603,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +622,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +641,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +659,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +676,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +686,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +703,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +713,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +745,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +762,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +779,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +789,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +798,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +816,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +836,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +860,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +879,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +908,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +922,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +958,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +997,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1180,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1224,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1396,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1726,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index af52fac..7152e6c
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -768,7 +768,7 @@ CopyFrom(CopyFromState cstate)
 	estate->es_rteperminfos = cstate->rteperminfos;
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index a5115b9..7f62173
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -985,11 +985,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1013,10 +1015,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1044,6 +1047,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index 651ad24..b1d8256
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index f419c47..68de1bd
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -170,11 +170,13 @@ static TupleTableSlot *internalGetUpdate
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2690,13 +2692,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2737,9 +2740,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2754,8 +2758,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2776,7 +2782,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2802,22 +2808,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2879,9 +2895,28 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				ExecUpdatePrepareSlot(resultRelInfo, newslot, context->estate);
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, mtstate->canSetTag, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, mtstate->canSetTag,
+										   &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2899,7 +2934,25 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+				}
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3671,7 +3724,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3749,7 +3803,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3782,9 +3837,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3856,7 +3930,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4032,6 +4107,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4053,7 +4132,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4129,8 +4208,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
new file mode 100644
index cd68942..fa29c90
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -7109,7 +7109,6 @@ make_modifytable(PlannerInfo *root, Plan
 			RangeTblEntry *rte = planner_rt_fetch(rti, root);
 
 			Assert(rte->rtekind == RTE_RELATION);
-			Assert(operation != CMD_MERGE);
 			if (rte->relkind == RELKIND_FOREIGN_TABLE)
 				fdwroutine = GetFdwRoutineByRelId(rte->relid);
 			else
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 37a7af8..dad4920
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -187,12 +187,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
new file mode 100644
index c6d747b..027d2be
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -157,15 +157,14 @@ preprocess_targetlist(PlannerInfo *root)
 			/*
 			 * Add resjunk entries for any Vars used in each action's
 			 * targetlist and WHEN condition that belong to relations other
-			 * than target.  Note that aggregates, window functions and
-			 * placeholder vars are not possible anywhere in MERGE's WHEN
-			 * clauses.  (PHVs may be added later, but they don't concern us
-			 * here.)
+			 * than target.  Note that aggregates and window functions are not
+			 * possible anywhere in MERGE's WHEN clauses, but PlaceHolderVars
+			 * may have been added by subquery pullup.
 			 */
 			vars = pull_var_clause((Node *)
 								   list_concat_copy((List *) action->qual,
 													action->targetList),
-								   0);
+								   PVC_INCLUDE_PLACEHOLDERS);
 			foreach(l2, vars)
 			{
 				Var		   *var = (Var *) lfirst(l2);
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index cd45ab4..73cde37
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -846,8 +846,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index d886637..ec82c64
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index c74bac2..c02ef35
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -85,10 +85,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1462,7 +1462,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1470,7 +1470,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1639,11 +1639,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1651,10 +1652,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1663,6 +1660,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1735,9 +1749,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1745,7 +1759,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1755,6 +1770,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2437,11 +2453,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2457,6 +2480,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -2998,6 +3049,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3010,6 +3153,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3033,55 +3177,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3107,6 +3245,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3135,6 +3292,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3143,6 +3308,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3206,8 +3395,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3329,7 +3518,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3352,6 +3542,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3444,10 +3660,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3499,11 +3715,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3557,14 +3774,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3834,7 +4050,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3878,7 +4094,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3888,7 +4105,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3900,39 +4118,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 980f583..9e8d495
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -474,9 +474,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -485,6 +486,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -660,9 +664,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -671,6 +676,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 5e1882e..95e22d6
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index e7e25c0..765cd42
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 89335d9..8347ec6
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -179,6 +179,8 @@ typedef struct Query
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin;
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetSrcIdx;
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index bc53b21..bc4c989
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 2b578cc..2d2dc94
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,84 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- PlaceHolderVar in MERGE WHEN condition
+CREATE OR REPLACE VIEW rw_view2 AS SELECT *, 'xxx' AS c FROM base_tbl;
+CREATE TRIGGER rw_view2_ins_trig INSTEAD OF INSERT ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'r'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND c = 'xxx' THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | r0
+  1 | r1
+  2 | r2
+  3 | r3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1269,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1286,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1315,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1343,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1371,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1382,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1398,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1408,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1424,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1443,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1456,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1475,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1534,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1566,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1587,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1598,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1627,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1637,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1653,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1682,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1708,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1725,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1749,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1764,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1779,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1799,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1818,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1839,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1864,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1874,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2249,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2310,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2325,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2379,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2675,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2692,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2704,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2726,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3370,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index fdbcd70..27499f0
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index a6aebbc..a341d57
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,65 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- PlaceHolderVar in MERGE WHEN condition
+CREATE OR REPLACE VIEW rw_view2 AS SELECT *, 'xxx' AS c FROM base_tbl;
+CREATE TRIGGER rw_view2_ins_trig INSTEAD OF INSERT ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'r'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND c = 'xxx' THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +564,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +578,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +603,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +622,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +641,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +659,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +676,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +686,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +703,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +713,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +745,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +762,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +779,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +789,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +798,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +816,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +836,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +860,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +879,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +908,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +922,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +958,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +997,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1180,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1224,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1396,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1726,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index af52fac..7152e6c
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -768,7 +768,7 @@ CopyFrom(CopyFromState cstate)
 	estate->es_rteperminfos = cstate->rteperminfos;
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index a5115b9..7f62173
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -985,11 +985,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1013,10 +1015,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1044,6 +1047,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index 651ad24..b1d8256
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 1ac6517..5c3a2f4
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -170,11 +170,13 @@ static TupleTableSlot *internalGetUpdate
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2690,13 +2692,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2737,9 +2740,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2754,8 +2758,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2776,7 +2782,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2802,22 +2808,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2879,9 +2895,28 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				ExecUpdatePrepareSlot(resultRelInfo, newslot, context->estate);
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, mtstate->canSetTag, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, mtstate->canSetTag,
+										   &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2899,7 +2934,25 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+				}
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3671,7 +3724,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3749,7 +3803,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3782,9 +3837,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3856,7 +3930,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4032,6 +4107,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4053,7 +4132,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4129,8 +4208,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
new file mode 100644
index 1341304..3995436
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -7118,7 +7118,6 @@ make_modifytable(PlannerInfo *root, Plan
 			RangeTblEntry *rte = planner_rt_fetch(rti, root);
 
 			Assert(rte->rtekind == RTE_RELATION);
-			Assert(operation != CMD_MERGE);
 			if (rte->relkind == RELKIND_FOREIGN_TABLE)
 				fdwroutine = GetFdwRoutineByRelId(rte->relid);
 			else
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 870d84b..7035f0b
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetSrcIdx),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
new file mode 100644
index c6d747b..027d2be
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -157,15 +157,14 @@ preprocess_targetlist(PlannerInfo *root)
 			/*
 			 * Add resjunk entries for any Vars used in each action's
 			 * targetlist and WHEN condition that belong to relations other
-			 * than target.  Note that aggregates, window functions and
-			 * placeholder vars are not possible anywhere in MERGE's WHEN
-			 * clauses.  (PHVs may be added later, but they don't concern us
-			 * here.)
+			 * than target.  Note that aggregates and window functions are not
+			 * possible anywhere in MERGE's WHEN clauses, but PlaceHolderVars
+			 * may have been added by subquery pullup.
 			 */
 			vars = pull_var_clause((Node *)
 								   list_concat_copy((List *) action->qual,
 													action->targetList),
-								   0);
+								   PVC_INCLUDE_PLACEHOLDERS);
 			foreach(l2, vars)
 			{
 				Var		   *var = (Var *) lfirst(l2);
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 9d37738..8b111f8
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -890,8 +890,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index d886637..ec82c64
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index c74bac2..c02ef35
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -85,10 +85,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1462,7 +1462,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1470,7 +1470,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1639,11 +1639,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1651,10 +1652,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1663,6 +1660,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1735,9 +1749,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1745,7 +1759,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1755,6 +1770,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2437,11 +2453,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2457,6 +2480,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -2998,6 +3049,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3010,6 +3153,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3033,55 +3177,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3107,6 +3245,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3135,6 +3292,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3143,6 +3308,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3206,8 +3395,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3329,7 +3518,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3352,6 +3542,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3444,10 +3660,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3499,11 +3715,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3557,14 +3774,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3834,7 +4050,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3878,7 +4094,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3888,7 +4105,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3900,39 +4118,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 6f51c7e..6a5e3c4
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 5e1882e..95e22d6
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index e7e25c0..765cd42
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 855da99..1dd7a40
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -186,6 +186,8 @@ typedef struct Query
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetSrcIdx pg_node_attr(query_jumble_ignore);
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index bc53b21..bc4c989
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 2b578cc..b9f328f
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3362,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index fdbcd70..27499f0
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index a6aebbc..3c9ec1f
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1717,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index af52fac..7152e6c
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -768,7 +768,7 @@ CopyFrom(CopyFromState cstate)
 	estate->es_rteperminfos = cstate->rteperminfos;
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 39bfb48..fc8a710
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -985,11 +985,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1013,10 +1015,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1044,6 +1047,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index fd6ca8a..7a7bc3b
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 6f0543a..815a6bb
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -170,11 +170,13 @@ static TupleTableSlot *internalGetUpdate
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2687,13 +2689,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2734,9 +2737,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2751,8 +2755,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2773,7 +2779,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2799,22 +2805,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2876,9 +2892,27 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				ExecUpdatePrepareSlot(resultRelInfo, newslot, context->estate);
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, false, &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2896,7 +2930,25 @@ lmerge_matched:
 					result = TM_Ok;
 					break;
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+					{
+						result = TM_Ok;
+						break;	/* "do nothing" */
+					}
+					result = TM_Ok;
+				}
+				else
+				{
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+				}
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3667,7 +3719,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3745,7 +3798,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3778,9 +3832,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3852,7 +3925,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4028,6 +4102,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4049,7 +4127,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4125,8 +4203,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 870d84b..7035f0b
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetSrcIdx),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
new file mode 100644
index c6d747b..027d2be
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -157,15 +157,14 @@ preprocess_targetlist(PlannerInfo *root)
 			/*
 			 * Add resjunk entries for any Vars used in each action's
 			 * targetlist and WHEN condition that belong to relations other
-			 * than target.  Note that aggregates, window functions and
-			 * placeholder vars are not possible anywhere in MERGE's WHEN
-			 * clauses.  (PHVs may be added later, but they don't concern us
-			 * here.)
+			 * than target.  Note that aggregates and window functions are not
+			 * possible anywhere in MERGE's WHEN clauses, but PlaceHolderVars
+			 * may have been added by subquery pullup.
 			 */
 			vars = pull_var_clause((Node *)
 								   list_concat_copy((List *) action->qual,
 													action->targetList),
-								   0);
+								   PVC_INCLUDE_PLACEHOLDERS);
 			foreach(l2, vars)
 			{
 				Var		   *var = (Var *) lfirst(l2);
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 9d37738..8b111f8
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -890,8 +890,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index d886637..ec82c64
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index b6452e9..2a64534
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -85,10 +85,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1462,7 +1462,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1470,7 +1470,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1638,11 +1638,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1650,10 +1651,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1662,6 +1659,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1734,9 +1748,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1744,7 +1758,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1754,6 +1769,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2436,11 +2452,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2456,6 +2479,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -2997,6 +3048,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3009,6 +3152,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3032,55 +3176,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3106,6 +3244,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3134,6 +3291,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3142,6 +3307,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3205,8 +3394,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3328,7 +3517,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3351,6 +3541,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3443,10 +3659,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3498,11 +3714,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3556,14 +3773,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3833,7 +4049,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3904,7 +4120,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3914,7 +4131,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3926,39 +4144,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 04718f6..3c77258
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 5e1882e..95e22d6
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index e7e25c0..765cd42
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index f7d7f10..72edef2
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -186,6 +186,8 @@ typedef struct Query
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetSrcIdx pg_node_attr(query_jumble_ignore);
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index e1d3639..da521f2
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 0cbedc6..4fc0eb4
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3362,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index f085416..c04ed98
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index 7739b3b..bab4506
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1717,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 29cd1cf..c55bda7
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -762,7 +762,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index b32f419..2a6fd38
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -984,11 +984,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1012,10 +1014,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1043,6 +1046,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index fd6ca8a..7a7bc3b
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 3fa2b93..0dee552
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2701,13 +2703,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2748,9 +2751,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2765,8 +2769,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2787,7 +2793,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2813,22 +2819,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2887,8 +2903,23 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, false, &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2906,7 +2937,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3637,7 +3680,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3715,7 +3759,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3748,9 +3793,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3821,7 +3885,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -3997,6 +4062,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4018,7 +4087,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4094,8 +4163,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 870d84b..7035f0b
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetSrcIdx),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
new file mode 100644
index c6d747b..027d2be
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -157,15 +157,14 @@ preprocess_targetlist(PlannerInfo *root)
 			/*
 			 * Add resjunk entries for any Vars used in each action's
 			 * targetlist and WHEN condition that belong to relations other
-			 * than target.  Note that aggregates, window functions and
-			 * placeholder vars are not possible anywhere in MERGE's WHEN
-			 * clauses.  (PHVs may be added later, but they don't concern us
-			 * here.)
+			 * than target.  Note that aggregates and window functions are not
+			 * possible anywhere in MERGE's WHEN clauses, but PlaceHolderVars
+			 * may have been added by subquery pullup.
 			 */
 			vars = pull_var_clause((Node *)
 								   list_concat_copy((List *) action->qual,
 													action->targetList),
-								   0);
+								   PVC_INCLUDE_PLACEHOLDERS);
 			foreach(l2, vars)
 			{
 				Var		   *var = (Var *) lfirst(l2);
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 9d37738..8b111f8
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -890,8 +890,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index d886637..ec82c64
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 980dc18..2566bf3
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -86,10 +86,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1477,7 +1477,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1485,7 +1485,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1653,11 +1653,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1665,10 +1666,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1677,6 +1674,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1750,9 +1764,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1760,7 +1774,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1770,6 +1785,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2466,11 +2482,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2486,6 +2509,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3027,6 +3078,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3039,6 +3182,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3062,55 +3206,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3136,6 +3274,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3164,6 +3321,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3172,6 +3337,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3235,8 +3424,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3358,7 +3547,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3381,6 +3571,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3473,10 +3689,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3528,11 +3744,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3586,14 +3803,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3863,7 +4079,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3934,7 +4150,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3944,7 +4161,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3956,39 +4174,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index d28d0da..62cfc5b
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 8f12af7..9055033
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index 946abc0..66477d3
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 371aa0f..1bea659
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -185,6 +185,8 @@ typedef struct Query
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetSrcIdx pg_node_attr(query_jumble_ignore);
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index e32afc3..2e29176
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 0cbedc6..4fc0eb4
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3362,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index cae6902..8e177e6
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index 7739b3b..bab4506
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1717,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 321a7fa..b859d7d
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -762,7 +762,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index b32f419..2a6fd38
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -984,11 +984,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1012,10 +1014,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1043,6 +1046,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index fd6ca8a..7a7bc3b
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 3fa2b93..0dee552
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2701,13 +2703,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2748,9 +2751,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2765,8 +2769,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2787,7 +2793,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2813,22 +2819,32 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If not passed an old tuple, use tupleid to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (oldtuple == NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2887,8 +2903,23 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+				{
+					ExecUpdatePrepareSlot(resultRelInfo, newslot,
+										  context->estate);
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, false, &updateCxt);
+				}
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2906,7 +2937,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3637,7 +3680,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3715,7 +3759,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3748,9 +3793,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3821,7 +3885,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -3997,6 +4062,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4018,7 +4087,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4094,8 +4163,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 870d84b..7035f0b
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetSrcIdx.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetSrcIdx;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetSrcIdx),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 9d37738..8b111f8
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -890,8 +890,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index d886637..ec82c64
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -165,30 +165,31 @@ transformMergeStmt(ParseState *pstate, M
 
 	/*
 	 * Set up the MERGE target table.  The target table is added to the
-	 * namespace below and to joinlist in transform_MERGE_to_join, so don't
-	 * do it here.
+	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
+	 * it here.
+	 *
+	 * Initially mergeTargetSrcIdx is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetSrcIdx = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 980dc18..2566bf3
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -86,10 +86,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1477,7 +1477,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1485,7 +1485,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1653,11 +1653,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1665,10 +1666,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1677,6 +1674,23 @@ matchLocks(CmdType event,
 
 	nlocks = rulelocks->numLocks;
 
+	/* No rule support for MERGE */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		for (i = 0; i < nlocks; i++)
+		{
+			RewriteRule *oneLock = rulelocks->rules[i];
+
+			if (oneLock->event != CMD_SELECT)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot execute MERGE on relation \"%s\"",
+								RelationGetRelationName(relation)),
+						 errdetail("MERGE is not supported for relations with rules.")));
+		}
+		return NIL;
+	}
+
 	for (i = 0; i < nlocks; i++)
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
@@ -1750,9 +1764,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1760,7 +1774,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1770,6 +1785,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetSrcIdx unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2466,11 +2482,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2486,6 +2509,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3027,6 +3078,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3039,6 +3182,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3062,55 +3206,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3136,6 +3274,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3164,6 +3321,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3172,6 +3337,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3235,8 +3424,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3358,7 +3547,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through rewriteQuery, which will invoke
@@ -3381,6 +3571,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3473,10 +3689,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3528,11 +3744,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3586,14 +3803,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3863,7 +4079,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3934,7 +4150,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3944,7 +4161,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3956,39 +4174,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index d28d0da..62cfc5b
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetSrcIdx)
+				qry->mergeTargetSrcIdx += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetSrcIdx, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetSrcIdx == rt_index)
+				qry->mergeTargetSrcIdx = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 42e87b9..80ef935
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index 946abc0..66477d3
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -200,7 +200,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 028588f..0aa9655
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -185,6 +185,8 @@ typedef struct Query
 	List	   *mergeActionList;	/* list of actions for MERGE (only) */
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetSrcIdx pg_node_attr(query_jumble_ignore);
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 1ddc68b..1400967
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 0cbedc6..4fc0eb4
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2909,6 +3362,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 29a3548..a893ebc
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index 7739b3b..bab4506
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1463,6 +1717,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..5037419
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -360,7 +362,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +403,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +420,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0995fe0..5f562f8
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 80bca79..8743c6d
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -762,7 +762,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 4c5a7bb..a0b59b3
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1021,11 +1021,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1049,10 +1051,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1080,6 +1083,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index eb8a87f..e0f6ee3
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 2a5fec8..302d67d
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2710,13 +2712,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2757,9 +2760,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2774,8 +2778,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2796,7 +2802,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2822,22 +2828,33 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	Assert(tupleid != NULL || oldtuple != NULL);
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If passed a tupleid, use it to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (tupleid != NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2896,8 +2913,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, false, &updateCxt);
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2915,7 +2943,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3646,7 +3686,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3724,7 +3765,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3757,9 +3799,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3830,7 +3891,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4007,6 +4069,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4028,7 +4094,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4104,8 +4170,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 73ff407..64d4ecd
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetRelation.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetRelation;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetRelation),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index f456b3b..5d2ab3c
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -891,8 +891,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 91b1156..08fc46b
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -167,28 +167,29 @@ transformMergeStmt(ParseState *pstate, M
 	 * Set up the MERGE target table.  The target table is added to the
 	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
 	 * it here.
+	 *
+	 * Initially mergeTargetRelation is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetRelation = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index b486ab5..a4615a7
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -86,10 +86,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1479,7 +1479,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1487,7 +1487,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1655,11 +1655,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1667,10 +1668,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1683,6 +1680,15 @@ matchLocks(CmdType event,
 	{
 		RewriteRule *oneLock = rulelocks->rules[i];
 
+		/* Non-SELECT rules are not supported for MERGE */
+		if (parsetree->commandType == CMD_MERGE &&
+			oneLock->event != CMD_SELECT)
+			ereport(ERROR,
+					errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					errmsg("cannot execute MERGE on relation \"%s\"",
+						   RelationGetRelationName(relation)),
+					errdetail("MERGE is not supported for relations with rules."));
+
 		if (oneLock->event == CMD_UPDATE)
 			*hasUpdate = true;
 
@@ -1752,9 +1758,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1762,7 +1768,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1772,6 +1779,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetRelation unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2467,11 +2475,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2487,6 +2502,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3028,6 +3071,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3040,6 +3175,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3063,55 +3199,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3137,6 +3267,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3165,6 +3314,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3173,6 +3330,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3236,8 +3417,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3359,7 +3540,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through RewriteQuery, which will invoke
@@ -3382,6 +3564,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3474,10 +3682,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3529,11 +3737,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3587,14 +3796,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3864,7 +4072,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3935,7 +4143,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3945,7 +4154,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3957,39 +4167,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 32bd2f1..284580d
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetRelation)
+				qry->mergeTargetRelation += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetRelation == rt_index)
+				qry->mergeTargetRelation = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 935bb9b..4de1be7
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index ac02247..2ee05a0
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -210,7 +210,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index b3bec90..5012caa
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -186,6 +186,9 @@ typedef struct Query
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
 
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetRelation pg_node_attr(query_jumble_ignore);
+
 	List	   *targetList;		/* target list (of TargetEntry) */
 
 	/* OVERRIDING clause */
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 133d421..5a4a98f
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 1950e6f..4cde214
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2941,6 +3394,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 4cf6db9..fb6b97d
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index eaee0b7..89026ed
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1480,6 +1734,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..e8d9d3c
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -247,7 +249,8 @@ CREATE VIEW [ <replaceable>schema</repla
       <command>INSERT</command> or <command>UPDATE</command> command to be rewritten, then
       all check options will be ignored in the rewritten query, including any
       checks from automatically updatable views defined on top of the relation
-      with the <literal>INSTEAD</literal> rule.
+      with the <literal>INSTEAD</literal> rule.  <command>MERGE</command> is not
+      supported if the view or any of its base relations have rules.
      </para>
     </listitem>
    </varlistentry>
@@ -360,7 +363,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +404,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +421,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
@@ -443,14 +453,16 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     A more complex view that does not satisfy all these conditions is
-    read-only by default: the system will not allow an insert, update, or
-    delete on the view.  You can get the effect of an updatable view by
+    read-only by default: the system will not allow an <command>INSERT</command>,
+    <command>UPDATE</command>, <command>DELETE</command>, or <command>MERGE</command>
+    on the view.  You can get the effect of an updatable view by
     creating <literal>INSTEAD OF</literal> triggers on the view, which must
     convert attempted inserts, etc. on the view into appropriate actions
     on other tables.  For more information see <xref
     linkend="sql-createtrigger"/>.  Another possibility is to create rules
     (see <xref linkend="sql-createrule"/>), but in practice triggers are
-    easier to understand and use correctly.
+    easier to understand and use correctly.  Also note that <command>MERGE</command>
+    is not supported on relations with rules.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 0f61d47..738b49f
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index cec80ba..1dbe894
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -762,7 +762,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 4c5a7bb..a0b59b3
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1021,11 +1021,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1049,10 +1051,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1080,6 +1083,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index f6c3432..ca5d6cf
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 299c2c7..5177f23
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2710,13 +2712,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2757,9 +2760,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2774,8 +2778,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2796,7 +2802,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2822,22 +2828,33 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	Assert(tupleid != NULL || oldtuple != NULL);
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If passed a tupleid, use it to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (tupleid != NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2897,8 +2914,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, false, &updateCxt);
+
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
+				{
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, false, &updateCxt);
+
 				if (result == TM_Ok && updateCxt.updated)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
@@ -2916,7 +2944,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3647,7 +3687,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3725,7 +3766,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3758,9 +3800,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3831,7 +3892,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4009,6 +4071,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4030,7 +4096,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4106,8 +4172,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index 73ff407..64d4ecd
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetRelation.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetRelation;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetRelation),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index f456b3b..5d2ab3c
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -891,8 +891,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 91b1156..08fc46b
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -167,28 +167,29 @@ transformMergeStmt(ParseState *pstate, M
 	 * Set up the MERGE target table.  The target table is added to the
 	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
 	 * it here.
+	 *
+	 * Initially mergeTargetRelation is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetRelation = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index 41a3623..26af266
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -86,10 +86,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1465,7 +1465,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1473,7 +1473,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1641,11 +1641,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1653,10 +1654,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1674,7 +1671,7 @@ matchLocks(CmdType event,
 
 		/*
 		 * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
-		 * configured to not fire during the current sessions replication
+		 * configured to not fire during the current session's replication
 		 * role. ON SELECT rules will always be applied in order to keep views
 		 * working even in LOCAL or REPLICA role.
 		 */
@@ -1692,6 +1689,14 @@ matchLocks(CmdType event,
 					oneLock->enabled == RULE_DISABLED)
 					continue;
 			}
+
+			/* Non-SELECT rules are not supported for MERGE */
+			if (parsetree->commandType == CMD_MERGE)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot execute MERGE on relation \"%s\"",
+							   RelationGetRelationName(relation)),
+						errdetail("MERGE is not supported for relations with rules."));
 		}
 
 		if (oneLock->event == event)
@@ -1738,9 +1743,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1748,7 +1753,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1758,6 +1764,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetRelation unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2453,11 +2460,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2473,6 +2487,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3014,6 +3056,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3026,6 +3160,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3049,55 +3184,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3123,6 +3252,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3151,6 +3299,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3159,6 +3315,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3222,8 +3402,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3345,7 +3525,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through RewriteQuery, which will invoke
@@ -3368,6 +3549,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3460,10 +3667,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3515,11 +3722,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3573,14 +3781,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3850,7 +4057,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3921,7 +4128,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3931,7 +4139,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3943,39 +4152,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 32bd2f1..284580d
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetRelation)
+				qry->mergeTargetRelation += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetRelation == rt_index)
+				qry->mergeTargetRelation = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 93742fc..0b2bd92
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index e1eefb4..0958598
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -210,7 +210,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index cf7e790..61bbba7
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -185,6 +185,9 @@ typedef struct Query
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
 
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetRelation pg_node_attr(query_jumble_ignore);
+
 	List	   *targetList;		/* target list (of TargetEntry) */
 
 	/* OVERRIDING clause */
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 28a6d0b..ccb1005
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
new file mode 100644
index 1442c43..1f25560
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -3593,6 +3593,18 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 		DELETE
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 CREATE FUNCTION merge_sf_test()
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index a73c1f9..8a78f39
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2938,6 +3391,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 4cf6db9..fb6b97d
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
new file mode 100644
index 8b7e255..6944fbb
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -1277,6 +1277,19 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
 
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
+
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index eaee0b7..89026ed
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1480,6 +1734,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..e8d9d3c
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -247,7 +249,8 @@ CREATE VIEW [ <replaceable>schema</repla
       <command>INSERT</command> or <command>UPDATE</command> command to be rewritten, then
       all check options will be ignored in the rewritten query, including any
       checks from automatically updatable views defined on top of the relation
-      with the <literal>INSTEAD</literal> rule.
+      with the <literal>INSTEAD</literal> rule.  <command>MERGE</command> is not
+      supported if the view or any of its base relations have rules.
      </para>
     </listitem>
    </varlistentry>
@@ -360,7 +363,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +404,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +421,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
@@ -443,14 +453,16 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     A more complex view that does not satisfy all these conditions is
-    read-only by default: the system will not allow an insert, update, or
-    delete on the view.  You can get the effect of an updatable view by
+    read-only by default: the system will not allow an <command>INSERT</command>,
+    <command>UPDATE</command>, <command>DELETE</command>, or <command>MERGE</command>
+    on the view.  You can get the effect of an updatable view by
     creating <literal>INSTEAD OF</literal> triggers on the view, which must
     convert attempted inserts, etc. on the view into appropriate actions
     on other tables.  For more information see <xref
     linkend="sql-createtrigger"/>.  Another possibility is to create rules
     (see <xref linkend="sql-createrule"/>), but in practice triggers are
-    easier to understand and use correctly.
+    easier to understand and use correctly.  Also note that <command>MERGE</command>
+    is not supported on relations with rules.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 655f7dc..7353c03
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 1fe70b9..c3bc897
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -767,7 +767,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 13a9b7d..5a99e4a
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1021,11 +1021,13 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
 	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
+	ListCell   *lc;
 
 	switch (resultRel->rd_rel->relkind)
 	{
@@ -1049,10 +1051,11 @@ CheckValidResultRel(ResultRelInfo *resul
 
 			/*
 			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * here should match ereport_view_not_updatable() in
+			 * rewriteHandler.c, except that we omit errdetail because we
+			 * haven't got the information handy (and given that we really
+			 * shouldn't get here anyway, it's not worth great exertion to
+			 * get).
 			 */
 			switch (operation)
 			{
@@ -1080,6 +1083,51 @@ CheckValidResultRel(ResultRelInfo *resul
 										RelationGetRelationName(resultRel)),
 								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
 					break;
+				case CMD_MERGE:
+
+					/*
+					 * Must have a suitable INSTEAD OF trigger for each MERGE
+					 * action.  Note that the error hints here differ from
+					 * above, since MERGE doesn't support rules.
+					 */
+					foreach(lc, mergeActions)
+					{
+						MergeAction *action = (MergeAction *) lfirst(lc);
+
+						switch (action->commandType)
+						{
+							case CMD_INSERT:
+								if (!trigDesc || !trigDesc->trig_insert_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot insert into view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.")));
+								break;
+							case CMD_UPDATE:
+								if (!trigDesc || !trigDesc->trig_update_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot update view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.")));
+								break;
+							case CMD_DELETE:
+								if (!trigDesc || !trigDesc->trig_delete_instead_row)
+									ereport(ERROR,
+											(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+											 errmsg("cannot delete from view \"%s\"",
+													RelationGetRelationName(resultRel)),
+											 errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.")));
+								break;
+							case CMD_NOTHING:
+								break;
+							default:
+								elog(ERROR, "unrecognized commandType: %d", action->commandType);
+								break;
+						}
+					}
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
 					break;
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index b22040a..429f0a8
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 9fc5abf..5957518
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2716,13 +2718,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2763,9 +2766,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2780,8 +2784,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2802,7 +2808,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2828,22 +2834,33 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	Assert(tupleid != NULL || oldtuple != NULL);
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If passed a tupleid, use it to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (tupleid != NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2903,20 +2920,33 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, canSetTag, &updateCxt);
 
-				/*
-				 * As in ExecUpdate(), if ExecUpdateAct() reports that a
-				 * cross-partition update was done, then there's nothing else
-				 * for us to do --- the UPDATE has been turned into a DELETE
-				 * and an INSERT, and we must not perform any of the usual
-				 * post-update tasks.
-				 */
-				if (updateCxt.crossPartUpdate)
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
 				{
-					mtstate->mt_merge_updated += 1;
-					return true;
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+				{
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, canSetTag,
+										   &updateCxt);
+
+					/*
+					 * As in ExecUpdate(), if ExecUpdateAct() reports that a
+					 * cross-partition update was done, then there's nothing
+					 * else for us to do --- the UPDATE has been turned into a
+					 * DELETE and an INSERT, and we must not perform any of
+					 * the usual post-update tasks.
+					 */
+					if (updateCxt.crossPartUpdate)
+					{
+						mtstate->mt_merge_updated += 1;
+						return true;
+					}
 				}
 
 				if (result == TM_Ok && updateCxt.updated)
@@ -2936,7 +2966,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3667,7 +3709,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3745,7 +3788,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3778,9 +3822,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3851,7 +3914,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4029,6 +4093,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4050,7 +4118,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4126,8 +4194,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index aa83dd3..1a9df38
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetRelation.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetRelation;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetRelation),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 51fdeac..6ba4eba
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -891,8 +891,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 5f6a683..091293c
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -167,28 +167,29 @@ transformMergeStmt(ParseState *pstate, M
 	 * Set up the MERGE target table.  The target table is added to the
 	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
 	 * it here.
+	 *
+	 * Initially mergeTargetRelation is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetRelation = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index f60b34d..91f8e4d
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -87,10 +87,10 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
+static bool view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1482,7 +1482,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1490,7 +1490,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1658,11 +1658,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1670,10 +1671,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1691,7 +1688,7 @@ matchLocks(CmdType event,
 
 		/*
 		 * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
-		 * configured to not fire during the current sessions replication
+		 * configured to not fire during the current session's replication
 		 * role. ON SELECT rules will always be applied in order to keep views
 		 * working even in LOCAL or REPLICA role.
 		 */
@@ -1709,6 +1706,14 @@ matchLocks(CmdType event,
 					oneLock->enabled == RULE_DISABLED)
 					continue;
 			}
+
+			/* Non-SELECT rules are not supported for MERGE */
+			if (parsetree->commandType == CMD_MERGE)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot execute MERGE on relation \"%s\"",
+							   RelationGetRelationName(relation)),
+						errdetail("MERGE is not supported for relations with rules."));
 		}
 
 		if (oneLock->event == event)
@@ -1755,9 +1760,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1765,7 +1770,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1775,6 +1781,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetRelation unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2470,11 +2477,18 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
 static bool
-view_has_instead_trigger(Relation view, CmdType event)
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
+	ListCell   *lc;
 
 	switch (event)
 	{
@@ -2490,6 +2504,34 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach(lc, mergeActionList)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3031,6 +3073,98 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * ereport_view_not_updatable -
+ *	  Report an error from an attempt to update a non-updatable view.
+ *
+ * The error messages here match execMain.c's CheckValidResultRel, except that
+ * the executor doesn't have access to the same the error detail that we have
+ * here.  In principle, those executor checks are unnecessary, but we keep
+ * them just in case.
+ */
+static void
+ereport_view_not_updatable(Relation view,
+						   CmdType command,
+						   List *mergeActions,
+						   const char *detail)
+{
+	ListCell   *lc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					errdetail_internal("%s", _(detail)),
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+			/* Different hints, since MERGE doesn't support rules */
+			foreach(lc, mergeActions)
+			{
+				MergeAction *action = (MergeAction *) lfirst(lc);
+
+				if (action->commandType != CMD_NOTHING &&
+					!view_has_instead_trigger(view, action->commandType, NIL))
+				{
+					switch (action->commandType)
+					{
+						case CMD_INSERT:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+							break;
+						case CMD_UPDATE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+							break;
+						case CMD_DELETE:
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									errdetail_internal("%s", _(detail)),
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+							break;
+						default:
+							elog(ERROR, "unrecognized commandType: %d", action->commandType);
+							break;
+					}
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3043,6 +3177,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3066,55 +3201,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		ereport_view_not_updatable(view,
+								   parsetree->commandType,
+								   parsetree->mergeActionList,
+								   auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3140,6 +3269,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3168,6 +3316,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3176,6 +3332,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3239,8 +3419,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3362,7 +3542,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through RewriteQuery, which will invoke
@@ -3385,6 +3566,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3477,10 +3684,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3532,11 +3739,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3590,14 +3798,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3867,7 +4074,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3938,7 +4145,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3948,7 +4156,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3960,39 +4169,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				ereport_view_not_updatable(rt_entry_relation,
+										   parsetree->commandType,
+										   parsetree->mergeActionList,
+										   gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 76c97a5..191f2dc
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetRelation)
+				qry->mergeTargetRelation += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetRelation == rt_index)
+				qry->mergeTargetRelation = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index ada711d..b81d427
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index 5e8c335..9770752
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -210,7 +210,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 476d55d..dc66f5a
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -178,6 +178,9 @@ typedef struct Query
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
 
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetRelation pg_node_attr(query_jumble_ignore);
+
 	List	   *targetList;		/* target list (of TargetEntry) */
 
 	/* OVERRIDING clause */
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index f87905f..01d5374
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
new file mode 100644
index abc944e..f6070fc
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -3622,6 +3622,18 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 		DELETE
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 CREATE FUNCTION merge_sf_test()
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 1950e6f..4cde214
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2941,6 +3394,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 66cb75a..7706f10
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
new file mode 100644
index 93aff4e..6924012
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -1277,6 +1277,19 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
 
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
+
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index eaee0b7..89026ed
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1480,6 +1734,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..e8d9d3c
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -247,7 +249,8 @@ CREATE VIEW [ <replaceable>schema</repla
       <command>INSERT</command> or <command>UPDATE</command> command to be rewritten, then
       all check options will be ignored in the rewritten query, including any
       checks from automatically updatable views defined on top of the relation
-      with the <literal>INSTEAD</literal> rule.
+      with the <literal>INSTEAD</literal> rule.  <command>MERGE</command> is not
+      supported if the view or any of its base relations have rules.
      </para>
     </listitem>
    </varlistentry>
@@ -360,7 +363,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +404,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +421,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
@@ -443,14 +453,16 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     A more complex view that does not satisfy all these conditions is
-    read-only by default: the system will not allow an insert, update, or
-    delete on the view.  You can get the effect of an updatable view by
+    read-only by default: the system will not allow an <command>INSERT</command>,
+    <command>UPDATE</command>, <command>DELETE</command>, or <command>MERGE</command>
+    on the view.  You can get the effect of an updatable view by
     creating <literal>INSTEAD OF</literal> triggers on the view, which must
     convert attempted inserts, etc. on the view into appropriate actions
     on other tables.  For more information see <xref
     linkend="sql-createtrigger"/>.  Another possibility is to create rules
     (see <xref linkend="sql-createrule"/>), but in practice triggers are
-    easier to understand and use correctly.
+    easier to understand and use correctly.  Also note that <command>MERGE</command>
+    is not supported on relations with rules.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index 655f7dc..7353c03
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -128,9 +128,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before the table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -138,6 +138,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -484,7 +494,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..11b1a10
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 1fe70b9..c3bc897
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -767,7 +767,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 13a9b7d..79ef46f
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -56,6 +56,7 @@
 #include "miscadmin.h"
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
+#include "rewrite/rewriteHandler.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "tcop/utility.h"
@@ -1017,14 +1018,18 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * Generally the parser and/or planner should have noticed any such mistake
  * already, but let's make sure.
  *
+ * For MERGE, mergeActions is the list of actions that may be performed.  The
+ * result relation is required to support every action, regardless of whether
+ * or not they are all executed.
+ *
  * Note: when changing this function, you probably also need to look at
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
-	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
 
 	switch (resultRel->rd_rel->relkind)
@@ -1048,42 +1053,14 @@ CheckValidResultRel(ResultRelInfo *resul
 		case RELKIND_VIEW:
 
 			/*
-			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * Okay only if there's a suitable INSTEAD OF trigger.  Otherwise,
+			 * complain, but omit errdetail because we haven't got the
+			 * information handy (and given that it really shouldn't happen,
+			 * it's not worth great exertion to get).
 			 */
-			switch (operation)
-			{
-				case CMD_INSERT:
-					if (!trigDesc || !trigDesc->trig_insert_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-					break;
-				case CMD_UPDATE:
-					if (!trigDesc || !trigDesc->trig_update_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-					break;
-				case CMD_DELETE:
-					if (!trigDesc || !trigDesc->trig_delete_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-					break;
-				default:
-					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
-					break;
-			}
+			if (!view_has_instead_trigger(resultRel, operation, mergeActions))
+				error_view_not_updatable(resultRel, operation, mergeActions,
+										 NULL);
 			break;
 		case RELKIND_MATVIEW:
 			if (!MatViewIncrementalMaintenanceIsEnabled())
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index b22040a..429f0a8
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 9fc5abf..5957518
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -151,11 +151,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2716,13 +2718,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2763,9 +2766,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2780,8 +2784,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2802,7 +2808,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2828,22 +2834,33 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	Assert(tupleid != NULL || oldtuple != NULL);
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If passed a tupleid, use it to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (tupleid != NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2903,20 +2920,33 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, canSetTag, &updateCxt);
 
-				/*
-				 * As in ExecUpdate(), if ExecUpdateAct() reports that a
-				 * cross-partition update was done, then there's nothing else
-				 * for us to do --- the UPDATE has been turned into a DELETE
-				 * and an INSERT, and we must not perform any of the usual
-				 * post-update tasks.
-				 */
-				if (updateCxt.crossPartUpdate)
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
 				{
-					mtstate->mt_merge_updated += 1;
-					return true;
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+				{
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, canSetTag,
+										   &updateCxt);
+
+					/*
+					 * As in ExecUpdate(), if ExecUpdateAct() reports that a
+					 * cross-partition update was done, then there's nothing
+					 * else for us to do --- the UPDATE has been turned into a
+					 * DELETE and an INSERT, and we must not perform any of
+					 * the usual post-update tasks.
+					 */
+					if (updateCxt.crossPartUpdate)
+					{
+						mtstate->mt_merge_updated += 1;
+						return true;
+					}
 				}
 
 				if (result == TM_Ok && updateCxt.updated)
@@ -2936,7 +2966,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3667,7 +3709,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3745,7 +3788,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3778,9 +3822,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3851,7 +3914,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4029,6 +4093,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4050,7 +4118,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4126,8 +4194,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index aa83dd3..1a9df38
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetRelation.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetRelation;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetRelation),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 51fdeac..6ba4eba
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -891,8 +891,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 5f6a683..091293c
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -167,28 +167,29 @@ transformMergeStmt(ParseState *pstate, M
 	 * Set up the MERGE target table.  The target table is added to the
 	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
 	 * it here.
+	 *
+	 * Initially mergeTargetRelation is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetRelation = qry->resultRelation;
 
 	/*
 	 * MERGE is unsupported in various cases
 	 */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index f60b34d..fb05b91
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -87,10 +87,9 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1482,7 +1481,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1490,7 +1489,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1658,11 +1657,12 @@ rewriteValuesRTEToNulls(Query *parsetree
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1670,10 +1670,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1691,7 +1687,7 @@ matchLocks(CmdType event,
 
 		/*
 		 * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
-		 * configured to not fire during the current sessions replication
+		 * configured to not fire during the current session's replication
 		 * role. ON SELECT rules will always be applied in order to keep views
 		 * working even in LOCAL or REPLICA role.
 		 */
@@ -1709,6 +1705,14 @@ matchLocks(CmdType event,
 					oneLock->enabled == RULE_DISABLED)
 					continue;
 			}
+
+			/* Non-SELECT rules are not supported for MERGE */
+			if (parsetree->commandType == CMD_MERGE)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot execute MERGE on relation \"%s\"",
+							   RelationGetRelationName(relation)),
+						errdetail("MERGE is not supported for relations with rules."));
 		}
 
 		if (oneLock->event == event)
@@ -1755,9 +1759,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1765,7 +1769,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1775,6 +1780,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetRelation unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2470,9 +2476,15 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
-static bool
-view_has_instead_trigger(Relation view, CmdType event)
+bool
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
 
@@ -2490,6 +2502,32 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach_node(MergeAction, action, mergeActionList)
+			{
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3031,6 +3069,105 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * error_view_not_updatable -
+ *	  Report an error due to an attempt to update a non-updatable view.
+ *
+ * Generally this is expected to be called from the rewriter, with suitable
+ * error detail explaining why the view is not updatable.  Note, however, that
+ * the executor also performs a just-in-case check that the target view is
+ * updatable.  That check is expected to never fail, but if it does, it will
+ * call this function with NULL error detail --- see CheckValidResultRel().
+ *
+ * Note: for MERGE, at least one of the actions in mergeActionList is expected
+ * to lack a suitable INSTEAD OF trigger --- see view_has_instead_trigger().
+ */
+void
+error_view_not_updatable(Relation view,
+						 CmdType command,
+						 List *mergeActionList,
+						 const char *detail)
+{
+	TriggerDesc *trigDesc = view->trigdesc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+
+			/*
+			 * Note that the error hints here differ from above, since MERGE
+			 * doesn't support rules.
+			 */
+			foreach_node(MergeAction, action, mergeActionList)
+			{
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+						break;
+					case CMD_NOTHING:
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3043,6 +3180,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3066,55 +3204,49 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach(lc, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
+	/* The view must be updatable, else fail */
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		error_view_not_updatable(view,
+								 parsetree->commandType,
+								 parsetree->mergeActionList,
+								 auto_update_detail);
+
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3140,6 +3272,25 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3168,6 +3319,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3176,6 +3335,30 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3239,8 +3422,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3362,7 +3545,8 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
 	 * Note that this destroys the resno ordering of the targetlist, but that
 	 * will be fixed when we recurse through RewriteQuery, which will invoke
@@ -3385,6 +3569,32 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach(lc, parsetree->mergeActionList)
+		{
+			MergeAction *action = (MergeAction *) lfirst(lc);
+			ListCell   *lc2;
+
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach(lc2, action->targetList)
+				{
+					TargetEntry *tle = (TargetEntry *) lfirst(lc2);
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3477,10 +3687,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3532,11 +3742,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3590,14 +3801,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3867,7 +4077,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3938,7 +4148,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3948,7 +4159,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
@@ -3960,39 +4172,10 @@ RewriteQuery(Query *parsetree, List *rew
 			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				error_view_not_updatable(rt_entry_relation,
+										 parsetree->commandType,
+										 parsetree->mergeActionList,
+										 gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 76c97a5..191f2dc
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetRelation)
+				qry->mergeTargetRelation += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetRelation == rt_index)
+				qry->mergeTargetRelation = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index ada711d..b81d427
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index 5e8c335..9770752
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -210,7 +210,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index 476d55d..dc66f5a
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -178,6 +178,9 @@ typedef struct Query
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
 
+	/* rtable index of target relation that MERGE pulls data from */
+	int			mergeTargetRelation pg_node_attr(query_jumble_ignore);
+
 	List	   *targetList;		/* target list (of TargetEntry) */
 
 	/* OVERRIDING clause */
diff --git a/src/include/rewrite/rewriteHandler.h b/src/include/rewrite/rewriteHandler.h
new file mode 100644
index 14d3f30..1b65cda
--- a/src/include/rewrite/rewriteHandler.h
+++ b/src/include/rewrite/rewriteHandler.h
@@ -25,11 +25,17 @@ extern void AcquireRewriteLocks(Query *p
 extern Node *build_column_default(Relation rel, int attrno);
 
 extern Query *get_view_query(Relation view);
+extern bool view_has_instead_trigger(Relation view, CmdType event,
+									 List *mergeActionList);
 extern const char *view_query_is_auto_updatable(Query *viewquery,
 												bool check_cols);
 extern int	relation_is_updatable(Oid reloid,
 								  List *outer_reloids,
 								  bool include_triggers,
 								  Bitmapset *include_cols);
+extern void error_view_not_updatable(Relation view,
+									 CmdType command,
+									 List *mergeActionList,
+									 const char *detail);
 
 #endif							/* REWRITEHANDLER_H */
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index f87905f..01d5374
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -138,16 +138,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
new file mode 100644
index abc944e..f6070fc
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -3622,6 +3622,18 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 		DELETE
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 CREATE FUNCTION merge_sf_test()
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 1950e6f..4cde214
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,8 +2667,16 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
@@ -2237,8 +2684,10 @@ SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2696,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2718,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2941,6 +3394,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 66cb75a..7706f10
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -98,15 +98,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
new file mode 100644
index 93aff4e..6924012
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -1277,6 +1277,19 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
 
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
+
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index eaee0b7..89026ed
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,8 +1387,14 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 SELECT * FROM base_tbl;
 
@@ -1480,6 +1734,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 

diff --git a/doc/src/sgml/ref/create_view.sgml b/doc/src/sgml/ref/create_view.sgml
new file mode 100644
index 3b26205..e8d9d3c
--- a/doc/src/sgml/ref/create_view.sgml
+++ b/doc/src/sgml/ref/create_view.sgml
@@ -192,12 +192,14 @@ CREATE VIEW [ <replaceable>schema</repla
     <listitem>
      <para>
       This option controls the behavior of automatically updatable views.  When
-      this option is specified, <command>INSERT</command> and <command>UPDATE</command>
+      this option is specified, <command>INSERT</command>,
+      <command>UPDATE</command>, and <command>MERGE</command>
       commands on the view will be checked to ensure that new rows satisfy the
       view-defining condition (that is, the new rows are checked to ensure that
       they are visible through the view).  If they are not, the update will be
       rejected.  If the <literal>CHECK OPTION</literal> is not specified,
-      <command>INSERT</command> and <command>UPDATE</command> commands on the view are
+      <command>INSERT</command>, <command>UPDATE</command>, and
+      <command>MERGE</command> commands on the view are
       allowed to create rows that are not visible through the view.  The
       following check options are supported:
 
@@ -247,7 +249,8 @@ CREATE VIEW [ <replaceable>schema</repla
       <command>INSERT</command> or <command>UPDATE</command> command to be rewritten, then
       all check options will be ignored in the rewritten query, including any
       checks from automatically updatable views defined on top of the relation
-      with the <literal>INSTEAD</literal> rule.
+      with the <literal>INSTEAD</literal> rule.  <command>MERGE</command> is not
+      supported if the view or any of its base relations have rules.
      </para>
     </listitem>
    </varlistentry>
@@ -360,7 +363,8 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     Simple views are automatically updatable: the system will allow
-    <command>INSERT</command>, <command>UPDATE</command> and <command>DELETE</command> statements
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command> statements
     to be used on the view in the same way as on a regular table.  A view is
     automatically updatable if it satisfies all of the following conditions:
 
@@ -400,13 +404,15 @@ CREATE VIEW vista AS SELECT text 'Hello
     An automatically updatable view may contain a mix of updatable and
     non-updatable columns.  A column is updatable if it is a simple reference
     to an updatable column of the underlying base relation; otherwise the
-    column is read-only, and an error will be raised if an <command>INSERT</command>
-    or <command>UPDATE</command> statement attempts to assign a value to it.
+    column is read-only, and an error will be raised if an
+    <command>INSERT</command>, <command>UPDATE</command>, or
+    <command>MERGE</command> statement attempts to assign a value to it.
    </para>
 
    <para>
     If the view is automatically updatable the system will convert any
-    <command>INSERT</command>, <command>UPDATE</command> or <command>DELETE</command> statement
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> statement
     on the view into the corresponding statement on the underlying base
     relation.  <command>INSERT</command> statements that have an <literal>ON
     CONFLICT UPDATE</literal> clause are fully supported.
@@ -415,17 +421,21 @@ CREATE VIEW vista AS SELECT text 'Hello
    <para>
     If an automatically updatable view contains a <literal>WHERE</literal>
     condition, the condition restricts which rows of the base relation are
-    available to be modified by <command>UPDATE</command> and <command>DELETE</command>
-    statements on the view.  However, an <command>UPDATE</command> is allowed to
+    available to be modified by <command>UPDATE</command>,
+    <command>DELETE</command>, and <command>MERGE</command>
+    statements on the view.  However, an <command>UPDATE</command> or
+    <command>MERGE</command> is allowed to
     change a row so that it no longer satisfies the <literal>WHERE</literal>
     condition, and thus is no longer visible through the view.  Similarly,
-    an <command>INSERT</command> command can potentially insert base-relation rows
+    an <command>INSERT</command> or <command>MERGE</command> command can
+    potentially insert base-relation rows
     that do not satisfy the <literal>WHERE</literal> condition and thus are not
     visible through the view (<literal>ON CONFLICT UPDATE</literal> may
     similarly affect an existing row not visible through the view).
     The <literal>CHECK OPTION</literal> may be used to prevent
-    <command>INSERT</command> and <command>UPDATE</command> commands from creating
-    such rows that are not visible through the view.
+    <command>INSERT</command>, <command>UPDATE</command>, and
+    <command>MERGE</command> commands from creating such rows that are not
+    visible through the view.
    </para>
 
    <para>
@@ -443,14 +453,16 @@ CREATE VIEW vista AS SELECT text 'Hello
 
    <para>
     A more complex view that does not satisfy all these conditions is
-    read-only by default: the system will not allow an insert, update, or
-    delete on the view.  You can get the effect of an updatable view by
+    read-only by default: the system will not allow an <command>INSERT</command>,
+    <command>UPDATE</command>, <command>DELETE</command>, or <command>MERGE</command>
+    on the view.  You can get the effect of an updatable view by
     creating <literal>INSTEAD OF</literal> triggers on the view, which must
     convert attempted inserts, etc. on the view into appropriate actions
     on other tables.  For more information see <xref
     linkend="sql-createtrigger"/>.  Another possibility is to create rules
     (see <xref linkend="sql-createrule"/>), but in practice triggers are
-    easier to understand and use correctly.
+    easier to understand and use correctly.  Also note that <command>MERGE</command>
+    is not supported on relations with rules.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index bb34ef9..7a8ac40
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -132,9 +132,9 @@ DELETE
     <term><replaceable class="parameter">target_table_name</replaceable></term>
     <listitem>
      <para>
-      The name (optionally schema-qualified) of the target table to merge into.
-      If <literal>ONLY</literal> is specified before the table name, matching
-      rows are updated or deleted in the named table only.  If
+      The name (optionally schema-qualified) of the target table or view to
+      merge into.  If <literal>ONLY</literal> is specified before a table
+      name, matching rows are updated or deleted in the named table only.  If
       <literal>ONLY</literal> is not specified, matching rows are also updated
       or deleted in any tables inheriting from the named table.  Optionally,
       <literal>*</literal> can be specified after the table name to explicitly
@@ -142,6 +142,16 @@ DELETE
       <literal>ONLY</literal> keyword and <literal>*</literal> option do not
       affect insert actions, which always insert into the named table only.
      </para>
+
+     <para>
+      If <replaceable class="parameter">target_table_name</replaceable> is a
+      view, it must either be automatically updatable with no
+      <literal>INSTEAD OF</literal> triggers, or it must have
+      <literal>INSTEAD OF</literal> triggers for every type of action
+      (<literal>INSERT</literal>, <literal>UPDATE</literal>, and
+      <literal>DELETE</literal>) specified in the <literal>WHEN</literal>
+      clauses.  Views with rules are not supported.
+     </para>
     </listitem>
    </varlistentry>
 
@@ -486,7 +496,11 @@ MERGE <replaceable class="parameter">tot
              the action's event type.
             </para>
            </listitem>
-          </orderedlist></para>
+          </orderedlist>
+          If the target relation is a view with <literal>INSTEAD OF ROW</literal>
+          triggers for the action's event type, they are used to perform the
+          action instead.
+         </para>
         </listitem>
        </orderedlist></para>
      </listitem>
diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml
new file mode 100644
index d229b94..784c16e
--- a/doc/src/sgml/rules.sgml
+++ b/doc/src/sgml/rules.sgml
@@ -797,9 +797,9 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
 
 <para>
     What happens if a view is named as the target relation for an
-    <command>INSERT</command>, <command>UPDATE</command>, or
-    <command>DELETE</command>?  Doing the substitutions
-    described above would give a query tree in which the result
+    <command>INSERT</command>, <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command>?  Doing the
+    substitutions described above would give a query tree in which the result
     relation points at a subquery range-table entry, which will not
     work.  There are several ways in which <productname>PostgreSQL</productname>
     can support the appearance of updating a view, however.
@@ -813,11 +813,12 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     If the subquery selects from a single base relation and is simple
     enough, the rewriter can automatically replace the subquery with the
     underlying base relation so that the <command>INSERT</command>,
-    <command>UPDATE</command>, or <command>DELETE</command> is applied to
-    the base relation in the appropriate way.  Views that are
-    <quote>simple enough</quote> for this are called <firstterm>automatically
-    updatable</firstterm>.  For detailed information on the kinds of view that can
-    be automatically updated, see <xref linkend="sql-createview"/>.
+    <command>UPDATE</command>, <command>DELETE</command>, or
+    <command>MERGE</command> is applied to the base relation in the
+    appropriate way.  Views that are <quote>simple enough</quote> for this
+    are called <firstterm>automatically updatable</firstterm>.  For detailed
+    information on the kinds of view that can be automatically updated, see
+    <xref linkend="sql-createview"/>.
 </para>
 
 <para>
@@ -827,10 +828,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     Rewriting works slightly differently
     in this case.  For <command>INSERT</command>, the rewriter does
     nothing at all with the view, leaving it as the result relation
-    for the query.  For <command>UPDATE</command> and
-    <command>DELETE</command>, it's still necessary to expand the
+    for the query.  For <command>UPDATE</command>, <command>DELETE</command>,
+    and <command>MERGE</command>, it's still necessary to expand the
     view query to produce the <quote>old</quote> rows that the command will
-    attempt to update or delete.  So the view is expanded as normal,
+    attempt to update, delete, or merge.  So the view is expanded as normal,
     but another unexpanded range-table entry is added to the query
     to represent the view in its capacity as the result relation.
 </para>
@@ -842,13 +843,13 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     list to identify the physical locations of the rows to be updated.
     This does not work if the result relation is a view, because a view
     does not have any <acronym>CTID</acronym>, since its rows do not have
-    actual physical locations. Instead, for an <command>UPDATE</command>
-    or <command>DELETE</command> operation, a special <literal>wholerow</literal>
-    entry is added to the target list, which expands to include all
-    columns from the view. The executor uses this value to supply the
-    <quote>old</quote> row to the <literal>INSTEAD OF</literal> trigger.  It is
-    up to the trigger to work out what to update based on the old and
-    new row values.
+    actual physical locations. Instead, for an <command>UPDATE</command>,
+    <command>DELETE</command>, or <command>MERGE</command> operation, a
+    special <literal>wholerow</literal> entry is added to the target list,
+    which expands to include all columns from the view. The executor uses this
+    value to supply the <quote>old</quote> row to the
+    <literal>INSTEAD OF</literal> trigger.  It is up to the trigger to work
+    out what to update based on the old and new row values.
 </para>
 
 <para>
@@ -857,7 +858,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 W
     <command>UPDATE</command>, and <command>DELETE</command> commands on
     a view. These rules will rewrite the command, typically into a command
     that updates one or more tables, rather than views. That is the topic
-    of <xref linkend="rules-update"/>.
+    of <xref linkend="rules-update"/>.  Note that this will not work with
+    <command>MERGE</command>, which currently does not support rules.
 </para>
 
 <para>
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
new file mode 100644
index 1fe70b9..c3bc897
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -767,7 +767,7 @@ CopyFrom(CopyFromState cstate)
 	ExecInitResultRelation(estate, resultRelInfo, 1);
 
 	/* Verify the named relation is a valid target for INSERT */
-	CheckValidResultRel(resultRelInfo, CMD_INSERT);
+	CheckValidResultRel(resultRelInfo, CMD_INSERT, NIL);
 
 	ExecOpenIndices(resultRelInfo, false);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
new file mode 100644
index 13a9b7d..79ef46f
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -56,6 +56,7 @@
 #include "miscadmin.h"
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
+#include "rewrite/rewriteHandler.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "tcop/utility.h"
@@ -1017,14 +1018,18 @@ InitPlan(QueryDesc *queryDesc, int eflag
  * Generally the parser and/or planner should have noticed any such mistake
  * already, but let's make sure.
  *
+ * For MERGE, mergeActions is the list of actions that may be performed.  The
+ * result relation is required to support every action, regardless of whether
+ * or not they are all executed.
+ *
  * Note: when changing this function, you probably also need to look at
  * CheckValidRowMarkRel.
  */
 void
-CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+					List *mergeActions)
 {
 	Relation	resultRel = resultRelInfo->ri_RelationDesc;
-	TriggerDesc *trigDesc = resultRel->trigdesc;
 	FdwRoutine *fdwroutine;
 
 	switch (resultRel->rd_rel->relkind)
@@ -1048,42 +1053,14 @@ CheckValidResultRel(ResultRelInfo *resul
 		case RELKIND_VIEW:
 
 			/*
-			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
-			 * here should match rewriteHandler.c's rewriteTargetView and
-			 * RewriteQuery, except that we omit errdetail because we haven't
-			 * got the information handy (and given that we really shouldn't
-			 * get here anyway, it's not worth great exertion to get).
+			 * Okay only if there's a suitable INSTEAD OF trigger.  Otherwise,
+			 * complain, but omit errdetail because we haven't got the
+			 * information handy (and given that it really shouldn't happen,
+			 * it's not worth great exertion to get).
 			 */
-			switch (operation)
-			{
-				case CMD_INSERT:
-					if (!trigDesc || !trigDesc->trig_insert_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-					break;
-				case CMD_UPDATE:
-					if (!trigDesc || !trigDesc->trig_update_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-					break;
-				case CMD_DELETE:
-					if (!trigDesc || !trigDesc->trig_delete_instead_row)
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(resultRel)),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-					break;
-				default:
-					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
-					break;
-			}
+			if (!view_has_instead_trigger(resultRel, operation, mergeActions))
+				error_view_not_updatable(resultRel, operation, mergeActions,
+										 NULL);
 			break;
 		case RELKIND_MATVIEW:
 			if (!MatViewIncrementalMaintenanceIsEnabled())
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
new file mode 100644
index b22040a..429f0a8
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -361,7 +361,7 @@ ExecFindPartition(ModifyTableState *mtst
 				if (rri)
 				{
 					/* Verify this ResultRelInfo allows INSERTs */
-					CheckValidResultRel(rri, CMD_INSERT);
+					CheckValidResultRel(rri, CMD_INSERT, NIL);
 
 					/*
 					 * Initialize information needed to insert this and
@@ -527,7 +527,7 @@ ExecInitPartitionInfo(ModifyTableState *
 	 * partition-key becomes a DELETE+INSERT operation, so this check is still
 	 * required when the operation is CMD_UPDATE.
 	 */
-	CheckValidResultRel(leaf_part_rri, CMD_INSERT);
+	CheckValidResultRel(leaf_part_rri, CMD_INSERT, NIL);
 
 	/*
 	 * Open partition indices.  The user may have asked to check for conflicts
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
new file mode 100644
index 9fc5abf..ff7ec84
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -109,7 +109,6 @@ typedef struct ModifyTableContext
  */
 typedef struct UpdateContext
 {
-	bool		updated;		/* did UPDATE actually occur? */
 	bool		crossPartUpdate;	/* was it a cross-partition update? */
 	TU_UpdateIndexes updateIndexes; /* Which index updates are required? */
 
@@ -151,11 +150,13 @@ static TupleTableSlot *ExecPrepareTupleR
 static TupleTableSlot *ExecMerge(ModifyTableContext *context,
 								 ResultRelInfo *resultRelInfo,
 								 ItemPointer tupleid,
+								 HeapTuple oldtuple,
 								 bool canSetTag);
 static void ExecInitMerge(ModifyTableState *mtstate, EState *estate);
 static bool ExecMergeMatched(ModifyTableContext *context,
 							 ResultRelInfo *resultRelInfo,
 							 ItemPointer tupleid,
+							 HeapTuple oldtuple,
 							 bool canSetTag);
 static void ExecMergeNotMatched(ModifyTableContext *context,
 								ResultRelInfo *resultRelInfo,
@@ -2042,7 +2043,6 @@ lreplace:
 									 &insert_destrel))
 		{
 			/* success! */
-			updateCxt->updated = true;
 			updateCxt->crossPartUpdate = true;
 
 			/*
@@ -2111,8 +2111,6 @@ lreplace:
 								true /* wait for commit */ ,
 								&context->tmfd, &updateCxt->lockmode,
 								&updateCxt->updateIndexes);
-	if (result == TM_Ok)
-		updateCxt->updated = true;
 
 	return result;
 }
@@ -2716,13 +2714,14 @@ ExecOnConflictUpdate(ModifyTableContext
  */
 static TupleTableSlot *
 ExecMerge(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-		  ItemPointer tupleid, bool canSetTag)
+		  ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	bool		matched;
 
 	/*-----
-	 * If we are dealing with a WHEN MATCHED case (tupleid is valid), we
-	 * execute the first action for which the additional WHEN MATCHED AND
+	 * If we are dealing with a WHEN MATCHED case (tupleid or oldtuple is
+	 * valid, depending on whether the result relation is a table or a view),
+	 * we execute the first action for which the additional WHEN MATCHED AND
 	 * quals pass.  If an action without quals is found, that action is
 	 * executed.
 	 *
@@ -2763,9 +2762,10 @@ ExecMerge(ModifyTableContext *context, R
 	 * from ExecMergeNotMatched to ExecMergeMatched, there is no risk of a
 	 * livelock.
 	 */
-	matched = tupleid != NULL;
+	matched = tupleid != NULL || oldtuple != NULL;
 	if (matched)
-		matched = ExecMergeMatched(context, resultRelInfo, tupleid, canSetTag);
+		matched = ExecMergeMatched(context, resultRelInfo, tupleid, oldtuple,
+								   canSetTag);
 
 	/*
 	 * Either we were dealing with a NOT MATCHED tuple or ExecMergeMatched()
@@ -2780,8 +2780,10 @@ ExecMerge(ModifyTableContext *context, R
 }
 
 /*
- * Check and execute the first qualifying MATCHED action. The current target
- * tuple is identified by tupleid.
+ * Check and execute the first qualifying MATCHED action.  If the target
+ * relation is a table, the current target tuple is identified by tupleid.
+ * Otherwise, if the target relation is a view, oldtuple is the current target
+ * tuple from the view.
  *
  * We start from the first WHEN MATCHED action and check if the WHEN quals
  * pass, if any. If the WHEN quals for the first action do not pass, we
@@ -2802,7 +2804,7 @@ ExecMerge(ModifyTableContext *context, R
  */
 static bool
 ExecMergeMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
-				 ItemPointer tupleid, bool canSetTag)
+				 ItemPointer tupleid, HeapTuple oldtuple, bool canSetTag)
 {
 	ModifyTableState *mtstate = context->mtstate;
 	TupleTableSlot *newslot;
@@ -2828,22 +2830,33 @@ ExecMergeMatched(ModifyTableContext *con
 	econtext->ecxt_innertuple = context->planSlot;
 	econtext->ecxt_outertuple = NULL;
 
+	/*
+	 * This routine is only invoked for matched rows, so we should either have
+	 * the tupleid of the target row, or an old tuple from the target wholerow
+	 * junk attr.
+	 */
+	Assert(tupleid != NULL || oldtuple != NULL);
+	if (oldtuple != NULL)
+		ExecForceStoreHeapTuple(oldtuple, resultRelInfo->ri_oldTupleSlot,
+								false);
+
 lmerge_matched:
 
 	/*
-	 * This routine is only invoked for matched rows, and we must have found
-	 * the tupleid of the target row in that case; fetch that tuple.
+	 * If passed a tupleid, use it to fetch the old target row.
 	 *
 	 * We use SnapshotAny for this because we might get called again after
 	 * EvalPlanQual returns us a new tuple, which may not be visible to our
 	 * MVCC snapshot.
 	 */
-
-	if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
-									   tupleid,
-									   SnapshotAny,
-									   resultRelInfo->ri_oldTupleSlot))
-		elog(ERROR, "failed to fetch the target tuple");
+	if (tupleid != NULL)
+	{
+		if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
+										   tupleid,
+										   SnapshotAny,
+										   resultRelInfo->ri_oldTupleSlot))
+			elog(ERROR, "failed to fetch the target tuple");
+	}
 
 	foreach(l, resultRelInfo->ri_matchedMergeAction)
 	{
@@ -2903,23 +2916,36 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecUpdateAct(context, resultRelInfo, tupleid, NULL,
-									   newslot, canSetTag, &updateCxt);
 
-				/*
-				 * As in ExecUpdate(), if ExecUpdateAct() reports that a
-				 * cross-partition update was done, then there's nothing else
-				 * for us to do --- the UPDATE has been turned into a DELETE
-				 * and an INSERT, and we must not perform any of the usual
-				 * post-update tasks.
-				 */
-				if (updateCxt.crossPartUpdate)
+				/* INSTEAD OF ROW UPDATE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_update_instead_row)
 				{
-					mtstate->mt_merge_updated += 1;
-					return true;
+					if (!ExecIRUpdateTriggers(estate, resultRelInfo,
+											  oldtuple, newslot))
+						return true;	/* "do nothing" */
+				}
+				else
+				{
+					result = ExecUpdateAct(context, resultRelInfo, tupleid,
+										   NULL, newslot, canSetTag,
+										   &updateCxt);
+
+					/*
+					 * As in ExecUpdate(), if ExecUpdateAct() reports that a
+					 * cross-partition update was done, then there's nothing
+					 * else for us to do --- the UPDATE has been turned into a
+					 * DELETE and an INSERT, and we must not perform any of
+					 * the usual post-update tasks.
+					 */
+					if (updateCxt.crossPartUpdate)
+					{
+						mtstate->mt_merge_updated += 1;
+						return true;
+					}
 				}
 
-				if (result == TM_Ok && updateCxt.updated)
+				if (result == TM_Ok)
 				{
 					ExecUpdateEpilogue(context, &updateCxt, resultRelInfo,
 									   tupleid, NULL, newslot);
@@ -2936,7 +2962,19 @@ lmerge_matched:
 						return true;	/* "do nothing" */
 					break;		/* concurrent update/delete */
 				}
-				result = ExecDeleteAct(context, resultRelInfo, tupleid, false);
+
+				/* INSTEAD OF ROW DELETE Triggers */
+				if (resultRelInfo->ri_TrigDesc &&
+					resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
+				{
+					if (!ExecIRDeleteTriggers(estate, resultRelInfo,
+											  oldtuple))
+						return true;	/* "do nothing" */
+				}
+				else
+					result = ExecDeleteAct(context, resultRelInfo, tupleid,
+										   false);
+
 				if (result == TM_Ok)
 				{
 					ExecDeleteEpilogue(context, resultRelInfo, tupleid, NULL,
@@ -3667,7 +3705,8 @@ ExecModifyTable(PlanState *pstate)
 				{
 					EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-					ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+					ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+							  node->canSetTag);
 					continue;	/* no RETURNING support yet */
 				}
 
@@ -3745,7 +3784,8 @@ ExecModifyTable(PlanState *pstate)
 					{
 						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
 
-						ExecMerge(&context, node->resultRelInfo, NULL, node->canSetTag);
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
 						continue;	/* no RETURNING support yet */
 					}
 
@@ -3778,9 +3818,28 @@ ExecModifyTable(PlanState *pstate)
 				datum = ExecGetJunkAttribute(slot,
 											 resultRelInfo->ri_RowIdAttNo,
 											 &isNull);
-				/* shouldn't ever get a null result... */
+
+				/*
+				 * For commands other than MERGE, any tuples having a null row
+				 * identifier are errors.  For MERGE, we may need to handle
+				 * them as WHEN NOT MATCHED clauses if any, so do that.
+				 *
+				 * Note that we use the node's toplevel resultRelInfo, not any
+				 * specific partition's.
+				 */
 				if (isNull)
+				{
+					if (operation == CMD_MERGE)
+					{
+						EvalPlanQualSetSlot(&node->mt_epqstate, context.planSlot);
+
+						ExecMerge(&context, node->resultRelInfo, NULL, NULL,
+								  node->canSetTag);
+						continue;	/* no RETURNING support yet */
+					}
+
 					elog(ERROR, "wholerow is NULL");
+				}
 
 				oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
 				oldtupdata.t_len =
@@ -3851,7 +3910,8 @@ ExecModifyTable(PlanState *pstate)
 				break;
 
 			case CMD_MERGE:
-				slot = ExecMerge(&context, resultRelInfo, tupleid, node->canSetTag);
+				slot = ExecMerge(&context, resultRelInfo, tupleid, oldtuple,
+								 node->canSetTag);
 				break;
 
 			default:
@@ -4029,6 +4089,10 @@ ExecInitModifyTable(ModifyTable *node, E
 	foreach(l, node->resultRelations)
 	{
 		Index		resultRelation = lfirst_int(l);
+		List	   *mergeActions = NIL;
+
+		if (node->mergeActionLists)
+			mergeActions = list_nth(node->mergeActionLists, i);
 
 		if (resultRelInfo != mtstate->rootResultRelInfo)
 		{
@@ -4050,7 +4114,7 @@ ExecInitModifyTable(ModifyTable *node, E
 		/*
 		 * Verify result relation is a valid target for the current operation
 		 */
-		CheckValidResultRel(resultRelInfo, operation);
+		CheckValidResultRel(resultRelInfo, operation, mergeActions);
 
 		resultRelInfo++;
 		i++;
@@ -4126,8 +4190,6 @@ ExecInitModifyTable(ModifyTable *node, E
 			}
 			else
 			{
-				/* No support for MERGE */
-				Assert(operation != CMD_MERGE);
 				/* Other valid target relkinds must provide wholerow */
 				resultRelInfo->ri_RowIdAttNo =
 					ExecFindJunkAttributeInTlist(subplan->targetlist,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
new file mode 100644
index aa83dd3..1a9df38
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -198,12 +198,17 @@ transform_MERGE_to_join(Query *parse)
 
 	/*
 	 * Create a JOIN between the target and the source relation.
+	 *
+	 * Here the target is identified by parse->mergeTargetRelation.  For a
+	 * regular table, this will equal parse->resultRelation, but for a
+	 * trigger-updatable view, it will be the expanded view subquery that we
+	 * need to pull data from.
 	 */
 	joinexpr = makeNode(JoinExpr);
 	joinexpr->jointype = jointype;
 	joinexpr->isNatural = false;
 	joinexpr->larg = (Node *) makeNode(RangeTblRef);
-	((RangeTblRef *) joinexpr->larg)->rtindex = parse->resultRelation;
+	((RangeTblRef *) joinexpr->larg)->rtindex = parse->mergeTargetRelation;
 	joinexpr->rarg = linitial(parse->jointree->fromlist);	/* original join */
 	joinexpr->usingClause = NIL;
 	joinexpr->join_using_alias = NULL;
@@ -215,6 +220,18 @@ transform_MERGE_to_join(Query *parse)
 	/* Make the new join be the sole entry in the query's jointree */
 	parse->jointree->fromlist = list_make1(joinexpr);
 	parse->jointree->quals = NULL;
+
+	/*
+	 * If necessary, mark parse->targetlist entries that refer to the target
+	 * as nullable by the join.  Normally the targetlist will be empty for a
+	 * MERGE, but if the target is a trigger-updatable view, it will contain a
+	 * whole-row Var referring to the expanded view query.
+	 */
+	if (jointype == JOIN_RIGHT || jointype == JOIN_FULL)
+		parse->targetList = (List *)
+			add_nulling_relids((Node *) parse->targetList,
+							   bms_make_singleton(parse->mergeTargetRelation),
+							   bms_make_singleton(joinrti));
 }
 
 /*
diff --git a/src/backend/optimizer/util/appendinfo.c b/src/backend/optimizer/util/appendinfo.c
new file mode 100644
index 51fdeac..6ba4eba
--- a/src/backend/optimizer/util/appendinfo.c
+++ b/src/backend/optimizer/util/appendinfo.c
@@ -891,8 +891,7 @@ add_row_identity_columns(PlannerInfo *ro
 
 	Assert(commandType == CMD_UPDATE || commandType == CMD_DELETE || commandType == CMD_MERGE);
 
-	if (commandType == CMD_MERGE ||
-		relkind == RELKIND_RELATION ||
+	if (relkind == RELKIND_RELATION ||
 		relkind == RELKIND_MATVIEW ||
 		relkind == RELKIND_PARTITIONED_TABLE)
 	{
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
new file mode 100644
index 73f7a48..4356d61
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -172,28 +172,27 @@ transformMergeStmt(ParseState *pstate, M
 	 * Set up the MERGE target table.  The target table is added to the
 	 * namespace below and to joinlist in transform_MERGE_to_join, so don't do
 	 * it here.
+	 *
+	 * Initially mergeTargetRelation is the same as resultRelation, so data is
+	 * read from the table being updated.  However, that might be changed by
+	 * the rewriter, if the target is a trigger-updatable view, to allow
+	 * target data to be read from the expanded view query while updating the
+	 * original view relation.
 	 */
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
 										 stmt->relation->inh,
 										 false, targetPerms);
+	qry->mergeTargetRelation = qry->resultRelation;
 
-	/*
-	 * MERGE is unsupported in various cases
-	 */
+	/* The target relation must be a table or a view */
 	if (pstate->p_target_relation->rd_rel->relkind != RELKIND_RELATION &&
-		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE &&
+		pstate->p_target_relation->rd_rel->relkind != RELKIND_VIEW)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot execute MERGE on relation \"%s\"",
 						RelationGetRelationName(pstate->p_target_relation)),
 				 errdetail_relkind_not_supported(pstate->p_target_relation->rd_rel->relkind)));
-	if (pstate->p_target_relation->rd_rules != NULL &&
-		pstate->p_target_relation->rd_rules->numLocks > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot execute MERGE on relation \"%s\"",
-						RelationGetRelationName(pstate->p_target_relation)),
-				 errdetail("MERGE is not supported for relations with rules.")));
 
 	/* Now transform the source relation to produce the source RTE. */
 	transformFromClause(pstate,
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index f60b34d..b8839b5
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -87,10 +87,9 @@ static void rewriteValuesRTEToNulls(Quer
 static void markQueryForLocking(Query *qry, Node *jtnode,
 								LockClauseStrength strength, LockWaitPolicy waitPolicy,
 								bool pushedDown);
-static List *matchLocks(CmdType event, RuleLock *rulelocks,
+static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
-static bool view_has_instead_trigger(Relation view, CmdType event);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
 
 
@@ -1482,7 +1481,7 @@ rewriteValuesRTE(Query *parsetree, Range
 	 */
 	isAutoUpdatableView = false;
 	if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
-		!view_has_instead_trigger(target_relation, CMD_INSERT))
+		!view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
 	{
 		List	   *locks;
 		bool		hasUpdate;
@@ -1490,7 +1489,7 @@ rewriteValuesRTE(Query *parsetree, Range
 		ListCell   *l;
 
 		/* Look for an unconditional DO INSTEAD rule */
-		locks = matchLocks(CMD_INSERT, target_relation->rd_rules,
+		locks = matchLocks(CMD_INSERT, target_relation,
 						   parsetree->resultRelation, parsetree, &hasUpdate);
 
 		found = false;
@@ -1654,15 +1653,16 @@ rewriteValuesRTEToNulls(Query *parsetree
 
 /*
  * matchLocks -
- *	  match the list of locks and returns the matching rules
+ *	  match a relation's list of locks and returns the matching rules
  */
 static List *
 matchLocks(CmdType event,
-		   RuleLock *rulelocks,
+		   Relation relation,
 		   int varno,
 		   Query *parsetree,
 		   bool *hasUpdate)
 {
+	RuleLock   *rulelocks = relation->rd_rules;
 	List	   *matching_locks = NIL;
 	int			nlocks;
 	int			i;
@@ -1670,10 +1670,6 @@ matchLocks(CmdType event,
 	if (rulelocks == NULL)
 		return NIL;
 
-	/* No rule support for MERGE */
-	if (parsetree->commandType == CMD_MERGE)
-		return NIL;
-
 	if (parsetree->commandType != CMD_SELECT)
 	{
 		if (parsetree->resultRelation != varno)
@@ -1691,7 +1687,7 @@ matchLocks(CmdType event,
 
 		/*
 		 * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
-		 * configured to not fire during the current sessions replication
+		 * configured to not fire during the current session's replication
 		 * role. ON SELECT rules will always be applied in order to keep views
 		 * working even in LOCAL or REPLICA role.
 		 */
@@ -1709,6 +1705,14 @@ matchLocks(CmdType event,
 					oneLock->enabled == RULE_DISABLED)
 					continue;
 			}
+
+			/* Non-SELECT rules are not supported for MERGE */
+			if (parsetree->commandType == CMD_MERGE)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot execute MERGE on relation \"%s\"",
+							   RelationGetRelationName(relation)),
+						errdetail("MERGE is not supported for relations with rules."));
 		}
 
 		if (oneLock->event == event)
@@ -1755,9 +1759,9 @@ ApplyRetrieveRule(Query *parsetree,
 		 * For INSERT, we needn't do anything.  The unmodified RTE will serve
 		 * fine as the result relation.
 		 *
-		 * For UPDATE/DELETE, we need to expand the view so as to have source
-		 * data for the operation.  But we also need an unmodified RTE to
-		 * serve as the target.  So, copy the RTE and add the copy to the
+		 * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
+		 * source data for the operation.  But we also need an unmodified RTE
+		 * to serve as the target.  So, copy the RTE and add the copy to the
 		 * rangetable.  Note that the copy does not get added to the jointree.
 		 * Also note that there's a hack in fireRIRrules to avoid calling this
 		 * function again when it arrives at the copied RTE.
@@ -1765,7 +1769,8 @@ ApplyRetrieveRule(Query *parsetree,
 		if (parsetree->commandType == CMD_INSERT)
 			return parsetree;
 		else if (parsetree->commandType == CMD_UPDATE ||
-				 parsetree->commandType == CMD_DELETE)
+				 parsetree->commandType == CMD_DELETE ||
+				 parsetree->commandType == CMD_MERGE)
 		{
 			RangeTblEntry *newrte;
 			Var		   *var;
@@ -1775,6 +1780,7 @@ ApplyRetrieveRule(Query *parsetree,
 			newrte = copyObject(rte);
 			parsetree->rtable = lappend(parsetree->rtable, newrte);
 			parsetree->resultRelation = list_length(parsetree->rtable);
+			/* parsetree->mergeTargetRelation unchanged (use expanded view) */
 
 			/*
 			 * For the most part, Vars referencing the view should remain as
@@ -2470,9 +2476,15 @@ get_view_query(Relation view)
  * If it does, we don't want to treat it as auto-updatable.  This test can't
  * be folded into view_query_is_auto_updatable because it's not an error
  * condition.
+ *
+ * For MERGE, this will return true if there is an INSTEAD OF trigger for
+ * every action in mergeActionList, and false if there are any actions that
+ * lack an INSTEAD OF trigger.  If there are no data-modifying MERGE actions
+ * (only DO NOTHING actions), true is returned so that the view is treated
+ * as trigger-updatable, rather than erroring out if it's not auto-updatable.
  */
-static bool
-view_has_instead_trigger(Relation view, CmdType event)
+bool
+view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
 {
 	TriggerDesc *trigDesc = view->trigdesc;
 
@@ -2490,6 +2502,32 @@ view_has_instead_trigger(Relation view,
 			if (trigDesc && trigDesc->trig_delete_instead_row)
 				return true;
 			break;
+		case CMD_MERGE:
+			foreach_node(MergeAction, action, mergeActionList)
+			{
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							return false;
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							return false;
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							return false;
+						break;
+					case CMD_NOTHING:
+						/* No trigger required */
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			return true;		/* no actions without an INSTEAD OF trigger */
 		default:
 			elog(ERROR, "unrecognized CmdType: %d", (int) event);
 			break;
@@ -3031,6 +3069,105 @@ adjust_view_column_set(Bitmapset *cols,
 
 
 /*
+ * error_view_not_updatable -
+ *	  Report an error due to an attempt to update a non-updatable view.
+ *
+ * Generally this is expected to be called from the rewriter, with suitable
+ * error detail explaining why the view is not updatable.  Note, however, that
+ * the executor also performs a just-in-case check that the target view is
+ * updatable.  That check is expected to never fail, but if it does, it will
+ * call this function with NULL error detail --- see CheckValidResultRel().
+ *
+ * Note: for MERGE, at least one of the actions in mergeActionList is expected
+ * to lack a suitable INSTEAD OF trigger --- see view_has_instead_trigger().
+ */
+void
+error_view_not_updatable(Relation view,
+						 CmdType command,
+						 List *mergeActionList,
+						 const char *detail)
+{
+	TriggerDesc *trigDesc = view->trigdesc;
+
+	switch (command)
+	{
+		case CMD_INSERT:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot insert into view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
+			break;
+		case CMD_UPDATE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot update view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
+			break;
+		case CMD_DELETE:
+			ereport(ERROR,
+					errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					errmsg("cannot delete from view \"%s\"",
+						   RelationGetRelationName(view)),
+					detail ? errdetail_internal("%s", _(detail)) : 0,
+					errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
+			break;
+		case CMD_MERGE:
+
+			/*
+			 * Note that the error hints here differ from above, since MERGE
+			 * doesn't support rules.
+			 */
+			foreach_node(MergeAction, action, mergeActionList)
+			{
+				switch (action->commandType)
+				{
+					case CMD_INSERT:
+						if (!trigDesc || !trigDesc->trig_insert_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot insert into view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
+						break;
+					case CMD_UPDATE:
+						if (!trigDesc || !trigDesc->trig_update_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot update view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
+						break;
+					case CMD_DELETE:
+						if (!trigDesc || !trigDesc->trig_delete_instead_row)
+							ereport(ERROR,
+									errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+									errmsg("cannot delete from view \"%s\"",
+										   RelationGetRelationName(view)),
+									detail ? errdetail_internal("%s", _(detail)) : 0,
+									errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
+						break;
+					case CMD_NOTHING:
+						break;
+					default:
+						elog(ERROR, "unrecognized commandType: %d", action->commandType);
+						break;
+				}
+			}
+			break;
+		default:
+			elog(ERROR, "unrecognized CmdType: %d", (int) command);
+			break;
+	}
+}
+
+
+/*
  * rewriteTargetView -
  *	  Attempt to rewrite a query where the target relation is a view, so that
  *	  the view's base relation becomes the target relation.
@@ -3043,6 +3180,7 @@ static Query *
 rewriteTargetView(Query *parsetree, Relation view)
 {
 	Query	   *viewquery;
+	bool		insert_or_update;
 	const char *auto_update_detail;
 	RangeTblRef *rtr;
 	int			base_rt_index;
@@ -3066,55 +3204,52 @@ rewriteTargetView(Query *parsetree, Rela
 	 */
 	viewquery = copyObject(get_view_query(view));
 
-	/* The view must be updatable, else fail */
-	auto_update_detail =
-		view_query_is_auto_updatable(viewquery,
-									 parsetree->commandType != CMD_DELETE);
+	/*
+	 * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE?  If so,
+	 * various additional checks on the view columns need to be applied, and
+	 * any view CHECK OPTIONs need to be enforced.
+	 */
+	insert_or_update =
+		(parsetree->commandType == CMD_INSERT ||
+		 parsetree->commandType == CMD_UPDATE);
 
-	if (auto_update_detail)
+	if (parsetree->commandType == CMD_MERGE)
 	{
-		/* messages here should match execMain.c's CheckValidResultRel */
-		switch (parsetree->commandType)
+		foreach_node(MergeAction, action, parsetree->mergeActionList)
 		{
-			case CMD_INSERT:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot insert into view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-				break;
-			case CMD_UPDATE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot update view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-				break;
-			case CMD_DELETE:
-				ereport(ERROR,
-						(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-						 errmsg("cannot delete from view \"%s\"",
-								RelationGetRelationName(view)),
-						 errdetail_internal("%s", _(auto_update_detail)),
-						 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-				break;
-			default:
-				elog(ERROR, "unrecognized CmdType: %d",
-					 (int) parsetree->commandType);
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				insert_or_update = true;
 				break;
+			}
 		}
 	}
 
 	/*
-	 * For INSERT/UPDATE the modified columns must all be updatable. Note that
-	 * we get the modified columns from the query's targetlist, not from the
-	 * result RTE's insertedCols and/or updatedCols set, since
-	 * rewriteTargetListIU may have added additional targetlist entries for
-	 * view defaults, and these must also be updatable.
+	 * The view must be updatable, else fail.
+	 *
+	 * If we are doing INSERT/UPDATE (or MERGE containing INSERT/UPDATE), we
+	 * also check that there is at least one updatable column.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	auto_update_detail =
+		view_query_is_auto_updatable(viewquery, insert_or_update);
+
+	if (auto_update_detail)
+		error_view_not_updatable(view,
+								 parsetree->commandType,
+								 parsetree->mergeActionList,
+								 auto_update_detail);
+
+	/*
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
+	 * columns must all be updatable. Note that we get the modified columns
+	 * from the query's targetlist, not from the result RTE's insertedCols
+	 * and/or updatedCols set, since rewriteTargetListIU may have added
+	 * additional targetlist entries for view defaults, and these must also be
+	 * updatable.
+	 */
+	if (insert_or_update)
 	{
 		Bitmapset  *modified_cols = NULL;
 		char	   *non_updatable_col;
@@ -3140,6 +3275,20 @@ rewriteTargetView(Query *parsetree, Rela
 			}
 		}
 
+		foreach_node(MergeAction, action, parsetree->mergeActionList)
+		{
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach_node(TargetEntry, tle, action->targetList)
+				{
+					if (!tle->resjunk)
+						modified_cols = bms_add_member(modified_cols,
+													   tle->resno - FirstLowInvalidHeapAttributeNumber);
+				}
+			}
+		}
+
 		auto_update_detail = view_cols_are_auto_updatable(viewquery,
 														  modified_cols,
 														  NULL,
@@ -3168,6 +3317,14 @@ rewriteTargetView(Query *parsetree, Rela
 									RelationGetRelationName(view)),
 							 errdetail_internal("%s", _(auto_update_detail))));
 					break;
+				case CMD_MERGE:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("cannot merge into column \"%s\" of view \"%s\"",
+									non_updatable_col,
+									RelationGetRelationName(view)),
+							 errdetail_internal("%s", _(auto_update_detail))));
+					break;
 				default:
 					elog(ERROR, "unrecognized CmdType: %d",
 						 (int) parsetree->commandType);
@@ -3176,6 +3333,28 @@ rewriteTargetView(Query *parsetree, Rela
 		}
 	}
 
+	/*
+	 * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
+	 * updatable view.  The caller already checked that there isn't a full set
+	 * of INSTEAD OF triggers, so this is to guard against having a partial
+	 * set (mixing auto-update and trigger-update actions in a single command
+	 * isn't supported).
+	 */
+	if (parsetree->commandType == CMD_MERGE)
+	{
+		foreach_node(MergeAction, action, parsetree->mergeActionList)
+		{
+			if (action->commandType != CMD_NOTHING &&
+				view_has_instead_trigger(view, action->commandType, NIL))
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("cannot merge into view \"%s\"",
+							   RelationGetRelationName(view)),
+						errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others."),
+						errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
+		}
+	}
+
 	/* Locate RTE describing the view in the outer query */
 	view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
 
@@ -3239,8 +3418,8 @@ rewriteTargetView(Query *parsetree, Rela
 	new_rt_index = list_length(parsetree->rtable);
 
 	/*
-	 * INSERTs never inherit.  For UPDATE/DELETE, we use the view query's
-	 * inheritance flag for the base relation.
+	 * INSERTs never inherit.  For UPDATE/DELETE/MERGE, we use the view
+	 * query's inheritance flag for the base relation.
 	 */
 	if (parsetree->commandType == CMD_INSERT)
 		new_rte->inh = false;
@@ -3362,11 +3541,12 @@ rewriteTargetView(Query *parsetree, Rela
 	/*
 	 * For INSERT/UPDATE we must also update resnos in the targetlist to refer
 	 * to columns of the base relation, since those indicate the target
-	 * columns to be affected.
+	 * columns to be affected.  Similarly, for MERGE we must update the resnos
+	 * in the merge action targetlists of any INSERT/UPDATE actions.
 	 *
-	 * Note that this destroys the resno ordering of the targetlist, but that
+	 * Note that this destroys the resno ordering of the targetlists, but that
 	 * will be fixed when we recurse through RewriteQuery, which will invoke
-	 * rewriteTargetListIU again on the updated targetlist.
+	 * rewriteTargetListIU again on the updated targetlists.
 	 */
 	if (parsetree->commandType != CMD_DELETE)
 	{
@@ -3385,6 +3565,28 @@ rewriteTargetView(Query *parsetree, Rela
 				elog(ERROR, "attribute number %d not found in view targetlist",
 					 tle->resno);
 		}
+
+		foreach_node(MergeAction, action, parsetree->mergeActionList)
+		{
+			if (action->commandType == CMD_INSERT ||
+				action->commandType == CMD_UPDATE)
+			{
+				foreach_node(TargetEntry, tle, action->targetList)
+				{
+					TargetEntry *view_tle;
+
+					if (tle->resjunk)
+						continue;
+
+					view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+					if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+						tle->resno = ((Var *) view_tle->expr)->varattno;
+					else
+						elog(ERROR, "attribute number %d not found in view targetlist",
+							 tle->resno);
+				}
+			}
+		}
 	}
 
 	/*
@@ -3477,10 +3679,10 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For UPDATE/DELETE, pull up any WHERE quals from the view.  We know that
-	 * any Vars in the quals must reference the one base relation, so we need
-	 * only adjust their varnos to reference the new target (just the same as
-	 * we did with the view targetlist).
+	 * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view.  We
+	 * know that any Vars in the quals must reference the one base relation,
+	 * so we need only adjust their varnos to reference the new target (just
+	 * the same as we did with the view targetlist).
 	 *
 	 * If it's a security-barrier view, its WHERE quals must be applied before
 	 * quals from the outer query, so we attach them to the RTE as security
@@ -3532,11 +3734,12 @@ rewriteTargetView(Query *parsetree, Rela
 	}
 
 	/*
-	 * For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
-	 * view specified WITH CASCADED CHECK OPTION, add the quals from the view
-	 * to the query's withCheckOptions list.
+	 * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
+	 * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
+	 * OPTION, add the quals from the view to the query's withCheckOptions
+	 * list.
 	 */
-	if (parsetree->commandType != CMD_DELETE)
+	if (insert_or_update)
 	{
 		bool		has_wco = RelationHasCheckOption(view);
 		bool		cascaded = RelationHasCascadedCheckOption(view);
@@ -3590,14 +3793,13 @@ rewriteTargetView(Query *parsetree, Rela
 				ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
 
 				/*
-				 * Make sure that the query is marked correctly if the added
-				 * qual has sublinks.  We can skip this check if the query is
-				 * already marked, or if the command is an UPDATE, in which
-				 * case the same qual will have already been added, and this
-				 * check will already have been done.
+				 * For INSERT, make sure that the query is marked correctly if
+				 * the added qual has sublinks.  This can be skipped for
+				 * UPDATE/MERGE, since the same qual will have already been
+				 * added above, and the check will already have been done.
 				 */
 				if (!parsetree->hasSubLinks &&
-					parsetree->commandType != CMD_UPDATE)
+					parsetree->commandType == CMD_INSERT)
 					parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
 			}
 		}
@@ -3867,7 +4069,7 @@ RewriteQuery(Query *parsetree, List *rew
 		/*
 		 * Collect and apply the appropriate rules.
 		 */
-		locks = matchLocks(event, rt_entry_relation->rd_rules,
+		locks = matchLocks(event, rt_entry_relation,
 						   result_relation, parsetree, &hasUpdate);
 
 		product_orig_rt_length = list_length(parsetree->rtable);
@@ -3938,7 +4140,8 @@ RewriteQuery(Query *parsetree, List *rew
 		 * automatically updated.  If so, we perform the necessary query
 		 * transformation here and add the resulting query to the
 		 * product_queries list, so that it gets recursively rewritten if
-		 * necessary.
+		 * necessary.  For MERGE, the view must be automatically updatable if
+		 * any of the merge actions lack a corresponding INSTEAD OF trigger.
 		 *
 		 * If the view cannot be automatically updated, we throw an error here
 		 * which is OK since the query would fail at runtime anyway.  Throwing
@@ -3948,51 +4151,19 @@ RewriteQuery(Query *parsetree, List *rew
 		 */
 		if (!instead &&
 			rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
-			!view_has_instead_trigger(rt_entry_relation, event))
+			!view_has_instead_trigger(rt_entry_relation, event,
+									  parsetree->mergeActionList))
 		{
 			/*
 			 * If there were any qualified INSTEAD rules, don't allow the view
 			 * to be automatically updated (an unqualified INSTEAD rule or
 			 * INSTEAD OF trigger is required).
-			 *
-			 * The messages here should match execMain.c's CheckValidResultRel
-			 * and in principle make those checks in executor unnecessary, but
-			 * we keep them just in case.
 			 */
 			if (qual_product != NULL)
-			{
-				switch (parsetree->commandType)
-				{
-					case CMD_INSERT:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot insert into view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
-						break;
-					case CMD_UPDATE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot update view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
-						break;
-					case CMD_DELETE:
-						ereport(ERROR,
-								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-								 errmsg("cannot delete from view \"%s\"",
-										RelationGetRelationName(rt_entry_relation)),
-								 errdetail("Views with conditional DO INSTEAD rules are not automatically updatable."),
-								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
-						break;
-					default:
-						elog(ERROR, "unrecognized CmdType: %d",
-							 (int) parsetree->commandType);
-						break;
-				}
-			}
+				error_view_not_updatable(rt_entry_relation,
+										 parsetree->commandType,
+										 parsetree->mergeActionList,
+										 gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
 
 			/*
 			 * Attempt to rewrite the query to automatically update the view.
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
new file mode 100644
index 76c97a5..191f2dc
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -496,9 +496,10 @@ OffsetVarNodes(Node *node, int offset, i
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
-		 * cannot be zero when recursing into a subquery, so there's no need
-		 * to have the same logic inside OffsetVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * OffsetVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -507,6 +508,9 @@ OffsetVarNodes(Node *node, int offset, i
 			if (qry->resultRelation)
 				qry->resultRelation += offset;
 
+			if (qry->mergeTargetRelation)
+				qry->mergeTargetRelation += offset;
+
 			if (qry->onConflict && qry->onConflict->exclRelIndex)
 				qry->onConflict->exclRelIndex += offset;
 
@@ -687,9 +691,10 @@ ChangeVarNodes(Node *node, int rt_index,
 		/*
 		 * If we are starting at a Query, and sublevels_up is zero, then we
 		 * must also fix rangetable indexes in the Query itself --- namely
-		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
-		 * when recursing into a subquery, so there's no need to have the same
-		 * logic inside ChangeVarNodes_walker.
+		 * resultRelation, mergeTargetRelation, exclRelIndex  and rowMarks
+		 * entries.  sublevels_up cannot be zero when recursing into a
+		 * subquery, so there's no need to have the same logic inside
+		 * ChangeVarNodes_walker.
 		 */
 		if (sublevels_up == 0)
 		{
@@ -698,6 +703,9 @@ ChangeVarNodes(Node *node, int rt_index,
 			if (qry->resultRelation == rt_index)
 				qry->resultRelation = new_index;
 
+			if (qry->mergeTargetRelation == rt_index)
+				qry->mergeTargetRelation = new_index;
+
 			/* this is unlikely to ever be used, but ... */
 			if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
 				qry->onConflict->exclRelIndex = new_index;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
new file mode 100644
index 151a521..aa1acf8
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -832,6 +832,7 @@ static const SchemaQuery Query_for_list_
 	.catname = "pg_catalog.pg_class c",
 	.selcondition =
 	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_VIEW) ", "
 	CppAsString2(RELKIND_PARTITIONED_TABLE) ") ",
 	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
 	.namespace = "c.relnamespace",
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
new file mode 100644
index 5e8c335..9770752
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -210,7 +210,8 @@ extern void standard_ExecutorEnd(QueryDe
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
-extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation);
+extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
+								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 							  Relation resultRelationDesc,
 							  Index resultRelationIndex,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
new file mode 100644
index baa6a97..71d6332
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -178,6 +178,14 @@ typedef struct Query
 	/* whether to use outer join */
 	bool		mergeUseOuterJoin pg_node_attr(query_jumble_ignore);
 
+	/*
+	 * rtable index of target relation for MERGE.  Initially, this is the same
+	 * as resultRelation, but after query rewriting, if the target relation is
+	 * a trigger-updatable view, this is the index of the expanded view
+	 * subquery, whereas resultRelation is the index of the target view.
+	 */
+	int			mergeTargetRelation pg_node_attr(query_jumble_ignore);
+
 	List	   *targetList;		/* target list (of TargetEntry) */
 
 	/* OVERRIDING clause */
diff --git a/src/include/rewrite/rewriteHandler.h b/src/include/rewrite/rewriteHandler.h
new file mode 100644
index 14d3f30..1b65cda
--- a/src/include/rewrite/rewriteHandler.h
+++ b/src/include/rewrite/rewriteHandler.h
@@ -25,11 +25,17 @@ extern void AcquireRewriteLocks(Query *p
 extern Node *build_column_default(Relation rel, int attrno);
 
 extern Query *get_view_query(Relation view);
+extern bool view_has_instead_trigger(Relation view, CmdType event,
+									 List *mergeActionList);
 extern const char *view_query_is_auto_updatable(Query *viewquery,
 												bool check_cols);
 extern int	relation_is_updatable(Oid reloid,
 								  List *outer_reloids,
 								  bool include_triggers,
 								  Bitmapset *include_cols);
+extern void error_view_not_updatable(Relation view,
+									 CmdType command,
+									 List *mergeActionList,
+									 const char *detail);
 
 #endif							/* REWRITEHANDLER_H */
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
new file mode 100644
index 28a6980..e3ebf46
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -139,16 +139,6 @@ COPY (
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-ERROR:  cannot execute MERGE on relation "tv"
-DETAIL:  This operation is not supported for views.
-DROP VIEW tv;
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
new file mode 100644
index b7488d7..0cd2c64
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -3623,6 +3623,18 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 		DELETE
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 CREATE FUNCTION merge_sf_test()
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
new file mode 100644
index 1950e6f..794cf9c
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -184,6 +184,24 @@ INSERT INTO ro_view13 VALUES (3, 'Row 3'
 ERROR:  cannot insert into view "ro_view13"
 DETAIL:  Views that do not select from a single table or view are not automatically updatable.
 HINT:  To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+ERROR:  cannot delete from view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+ERROR:  cannot update view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+ERROR:  cannot insert into view "ro_view13"
+DETAIL:  Views that do not select from a single table or view are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 ERROR:  cannot insert into column "ctid" of view "rw_view14"
@@ -205,6 +223,41 @@ SELECT * FROM base_tbl;
 (6 rows)
 
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+ERROR:  cannot merge into column "ctid" of view "rw_view14"
+DETAIL:  View columns that refer to system columns are not updatable.
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b       
+----+--------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Merged row 2
+  3 | Merged row 3
+(6 rows)
+
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | Row 1
+  2 | Row 2
+(5 rows)
+
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 ERROR:  cannot insert into column "upper" of view "rw_view15"
@@ -351,6 +404,10 @@ DELETE FROM rw_view16 WHERE a=2; -- shou
 ERROR:  cannot delete from view "rw_view16"
 DETAIL:  Views with conditional DO INSTEAD rules are not automatically updatable.
 HINT:  To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view16"
+DETAIL:  MERGE is not supported for relations with rules.
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 16 other objects
 DETAIL:  drop cascades to view ro_view1
@@ -417,6 +474,23 @@ SELECT * FROM base_tbl;
   5 | Unspecified
 (6 rows)
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |      b      
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | ROW 1
+  2 | Unspecified
+  5 | Unspecified
+(6 rows)
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
                     QUERY PLAN                    
 --------------------------------------------------
@@ -433,6 +507,50 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Index Cond: ((a > 0) AND (a = 5))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Merge on base_tbl
+   ->  Index Scan using base_tbl_pkey on base_tbl
+         Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Hash Right Join
+         Hash Cond: (base_tbl.a = generate_series.generate_series)
+         ->  Bitmap Heap Scan on base_tbl
+               Recheck Cond: (a > 0)
+               ->  Bitmap Index Scan on base_tbl_pkey
+                     Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series
+(9 rows)
+
 -- it's still updatable if we add a DO ALSO rule
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
 CREATE RULE base_tbl_log AS ON INSERT TO rw_view1 DO ALSO
@@ -509,6 +627,19 @@ SELECT * FROM rw_view2;
    4 | Row 4
 (3 rows)
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+ aaa |     bbb     
+-----+-------------
+   1 | Row 1
+   4 | R4
+   5 | Unspecified
+(3 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
                        QUERY PLAN                       
 --------------------------------------------------------
@@ -701,6 +832,10 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+ERROR:  cannot execute MERGE on relation "rw_view1"
+DETAIL:  MERGE is not supported for relations with rules.
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                            QUERY PLAN                           
 ----------------------------------------------------------------
@@ -932,6 +1067,21 @@ SELECT * FROM rw_view2;
  2 | Row 2
 (2 rows)
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  2 | R2
+  3 | R3
+(5 rows)
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
                         QUERY PLAN                        
 ----------------------------------------------------------
@@ -956,6 +1106,76 @@ EXPLAIN (costs off) DELETE FROM rw_view2
                      Index Cond: (a > 0)
 (7 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Merge on rw_view1 rw_view1_1
+   ->  Hash Right Join
+         Hash Cond: (rw_view1.a = x.x)
+         ->  Subquery Scan on rw_view1
+               Filter: (rw_view1.a < 10)
+               ->  Bitmap Heap Scan on base_tbl
+                     Recheck Cond: (a > 0)
+                     ->  Bitmap Index Scan on base_tbl_pkey
+                           Index Cond: (a > 0)
+         ->  Hash
+               ->  Function Scan on generate_series x
+(11 rows)
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot delete from view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot insert into view "rw_view1"
+DETAIL:  Views containing LIMIT or OFFSET are not automatically updatable.
+HINT:  To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+ERROR:  cannot merge into view "rw_view2"
+DETAIL:  MERGE is not supported for views with INSTEAD OF triggers for some actions, but not others.
+HINT:  To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers.
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+ a  |   b    
+----+--------
+ -2 | Row -2
+ -1 | Row -1
+  0 | Row 0
+  1 | R1
+  2 | R2
+  3 | R3
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -1041,6 +1261,14 @@ INSERT INTO rw_view1 VALUES ('Row 3', 3.
 ERROR:  permission denied for view rw_view1
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1050,6 +1278,16 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
@@ -1069,6 +1307,11 @@ DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1092,6 +1335,11 @@ ERROR:  permission denied for table base
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SELECT * FROM base_tbl;
  a |   b   | c 
 ---+-------+---
@@ -1115,6 +1363,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
@@ -1123,6 +1374,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1136,6 +1390,9 @@ SELECT * FROM rw_view1 FOR UPDATE;  -- n
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
@@ -1143,6 +1400,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1156,6 +1416,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1172,6 +1435,8 @@ SELECT * FROM rw_view1 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
@@ -1183,6 +1448,9 @@ SELECT * FROM rw_view2 FOR UPDATE;  -- n
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1199,30 +1467,38 @@ SELECT * FROM rw_view2 FOR UPDATE;
 (1 row)
 
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
  a |  b  | c 
 ---+-----+---
- 1 | bar | 1
+ 1 | fud | 1
 (1 row)
 
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1250,10 +1526,16 @@ UPDATE base_tbl SET a=a; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 DELETE FROM base_tbl; -- not allowed
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a,c) ON base_tbl TO regress_view_user2;
@@ -1276,10 +1558,18 @@ UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view1 SET bb=bb; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1289,6 +1579,9 @@ ERROR:  permission denied for view rw_vi
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
 GRANT INSERT, DELETE ON rw_view1 TO regress_view_user2;
@@ -1297,17 +1590,21 @@ INSERT INTO rw_view1 VALUES ('Row 4', 4.
 ERROR:  permission denied for table base_tbl
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
  a |   b   | c 
 ---+-------+---
- 3 | Row 3 | 3
  4 | Row 4 | 4
-(2 rows)
+(1 row)
 
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
@@ -1322,6 +1619,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
@@ -1329,6 +1629,9 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
+ERROR:  permission denied for view rw_view1
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
 GRANT UPDATE (a, b) ON base_tbl TO regress_view_user1;
@@ -1342,16 +1645,27 @@ SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for view rw_view1
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
 GRANT UPDATE (bb, cc) ON rw_view1 TO regress_view_user2;
@@ -1360,11 +1674,17 @@ SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user2;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user2;
@@ -1380,6 +1700,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 ERROR:  permission denied for table base_tbl
@@ -1389,6 +1717,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user3;
 GRANT UPDATE (a, c) ON base_tbl TO regress_view_user3;
@@ -1404,6 +1741,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user1;
 SET SESSION AUTHORIZATION regress_view_user1;
@@ -1411,6 +1756,9 @@ SELECT * FROM rw_view1;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view1 SET aa=aa;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1423,6 +1771,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1435,6 +1791,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 REVOKE SELECT, UPDATE ON base_tbl FROM regress_view_user2;
 SET SESSION AUTHORIZATION regress_view_user2;
@@ -1446,6 +1810,15 @@ UPDATE rw_view2 SET bbb=bbb;  -- not all
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
 ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
+ERROR:  permission denied for table base_tbl
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
  ccc | aaa |  bbb  
@@ -1458,6 +1831,14 @@ ERROR:  permission denied for view rw_vi
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 ERROR:  permission denied for table base_tbl
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+ERROR:  permission denied for view rw_view1
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+ERROR:  permission denied for table base_tbl
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 RESET SESSION AUTHORIZATION;
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -1475,6 +1856,8 @@ CREATE VIEW rw_view1 AS SELECT a AS aa,
 ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 SELECT * FROM base_tbl;
  a |      b       | c 
 ---+--------------+---
@@ -1483,7 +1866,8 @@ SELECT * FROM base_tbl;
  3 | Unspecified  | 3
  4 | Row 4        | 4
  5 | View default | 5
-(5 rows)
+ 6 | View default | 6
+(6 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
@@ -1857,6 +2241,38 @@ SELECT * FROM base_tbl_child ORDER BY a;
  20
 (6 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+  a   
+------
+ -199
+  -99
+  -39
+  -29
+  -20
+  -10
+  100
+  200
+(8 rows)
+
+SELECT * FROM base_tbl_child ORDER BY a;
+ a  
+----
+  3
+  4
+  7
+  8
+ 11
+ 21
+(6 rows)
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -1886,10 +2302,10 @@ UPDATE rw_view1 SET a = a + 1000 FROM ot
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
   a   
 ------
- -200
- -100
-  -40
-  -30
+ -199
+  -99
+  -39
+  -29
   -20
   -10
  1100
@@ -1901,8 +2317,8 @@ SELECT * FROM base_tbl_child ORDER BY a;
 ------
     3
     4
-   10
-   20
+   11
+   21
  1007
  1008
 (6 rows)
@@ -1955,16 +2371,39 @@ INSERT INTO rw_view1(a) VALUES (9); -- o
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
 ERROR:  new row violates check option for view "rw_view1"
 DETAIL:  Failing row contains (10, 10).
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
  a | b  
 ---+----
+ 1 | -1
  1 |  2
  2 |  3
- 1 | -1
  3 |  5
  9 | 10
 (5 rows)
 
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (11, 10).
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+ERROR:  new row violates check option for view "rw_view1"
+DETAIL:  Failing row contains (3, 3).
+SELECT * FROM base_tbl ORDER BY a, b;
+ a  | b  
+----+----
+  0 |  2
+  1 | -1
+  2 |  3
+  3 |  5
+  9 | 10
+ 10 | 11
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to view rw_view1
 -- WITH LOCAL/CASCADED CHECK OPTION
@@ -2228,17 +2667,31 @@ CREATE VIEW rw_view2 AS
 INSERT INTO rw_view2 VALUES (-5); -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-5).
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
 ERROR:  new row violates check option for view "rw_view2"
 DETAIL:  Failing row contains (-5).
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 10; -- should fail
+ERROR:  new row violates check option for view "rw_view2"
+DETAIL:  Failing row contains (-4).
 SELECT * FROM base_tbl;
  a  | b  
 ----+----
   5 | 10
+  6 | 10
  50 | 10
-(2 rows)
+ 60 | 10
+(4 rows)
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
 ALTER VIEW rw_view2 SET (check_option=cascaded);
@@ -2247,10 +2700,12 @@ UPDATE rw_view2 SET a = 200 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
-(3 rows)
+(5 rows)
 
 -- Neither local nor cascaded check options work with INSTEAD rules
 DROP TRIGGER rw_view1_trig ON rw_view1;
@@ -2267,14 +2722,16 @@ UPDATE rw_view2 SET a = -5 WHERE a = 5;
 SELECT * FROM base_tbl;
   a  | b  
 -----+----
+   6 | 10
   50 | 10
+  60 | 10
  100 | 10
  200 | 10
  -10 | 10
   20 | 10
   30 | 10
   -5 | 10
-(7 rows)
+(9 rows)
 
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
@@ -2375,6 +2832,11 @@ NOTICE:  snooped value: Harry
 DELETE FROM rw_view1 WHERE NOT snoop(person);
 NOTICE:  snooped value: Tom
 NOTICE:  snooped value: Harry
+MERGE INTO rw_view1 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
+NOTICE:  snooped value: Tom
+NOTICE:  snooped value: Harry
 EXPLAIN (costs off) SELECT * FROM rw_view1 WHERE snoop(person);
                   QUERY PLAN                   
 -----------------------------------------------
@@ -2400,6 +2862,21 @@ EXPLAIN (costs off) DELETE FROM rw_view1
          Filter: ((visibility = 'public'::text) AND (NOT snoop(person)))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
+                         QUERY PLAN                          
+-------------------------------------------------------------
+ Merge on base_tbl
+   ->  Nested Loop
+         Join Filter: (base_tbl.person = "*VALUES*".column1)
+         ->  Seq Scan on base_tbl
+               Filter: (visibility = 'public'::text)
+         ->  Materialize
+               ->  Values Scan on "*VALUES*"
+(7 rows)
+
 -- security barrier view on top of security barrier view
 CREATE VIEW rw_view2 WITH (security_barrier = true) AS
   SELECT * FROM rw_view1 WHERE snoop(person);
@@ -2449,6 +2926,13 @@ NOTICE:  snooped value: Tom
 NOTICE:  snooped value: Tom
 NOTICE:  snooped value: Harry
 NOTICE:  snooped value: Harry
+MERGE INTO rw_view2 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
+NOTICE:  snooped value: Tom
+NOTICE:  snooped value: Tom
+NOTICE:  snooped value: Harry
+NOTICE:  snooped value: Harry
 EXPLAIN (costs off) SELECT * FROM rw_view2 WHERE snoop(person);
                      QUERY PLAN                      
 -----------------------------------------------------
@@ -2476,6 +2960,20 @@ EXPLAIN (costs off) DELETE FROM rw_view2
          Filter: ((visibility = 'public'::text) AND snoop(person) AND (NOT snoop(person)))
 (3 rows)
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
+                               QUERY PLAN                                
+-------------------------------------------------------------------------
+ Merge on base_tbl
+   ->  Nested Loop
+         Join Filter: (base_tbl.person = "*VALUES*".column1)
+         ->  Seq Scan on base_tbl
+               Filter: ((visibility = 'public'::text) AND snoop(person))
+         ->  Values Scan on "*VALUES*"
+(6 rows)
+
 DROP TABLE base_tbl CASCADE;
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to view rw_view1
@@ -2941,6 +3439,29 @@ create view uv_ptv_wco as select * from
 insert into uv_ptv_wco values (1, 2);
 ERROR:  new row violates check option for view "uv_ptv_wco"
 DETAIL:  Failing row contains (1, 2, null).
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+ERROR:  MERGE command cannot affect row a second time
+HINT:  Ensure that not more than one source row matches any one target row.
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+ERROR:  no partition of relation "uv_pt1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (5).
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
+ tableoid | a | b | v 
+----------+---+---+---
+ uv_pt11  | 1 | 3 | 
+ uv_pt11  | 1 | 4 | 
+(2 rows)
+
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;
 -- check that wholerow vars appearing in WITH CHECK OPTION constraint expressions
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
new file mode 100644
index 82faa73..79a1868
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -100,15 +100,6 @@ COPY (
 ) TO stdout;
 
 -- unsupported relation types
--- view
-CREATE VIEW tv AS SELECT * FROM target;
-MERGE INTO tv t
-USING source s
-ON t.tid = s.sid
-WHEN NOT MATCHED THEN
-	INSERT DEFAULT VALUES;
-DROP VIEW tv;
-
 -- materialized view
 CREATE MATERIALIZED VIEW mv AS SELECT * FROM target;
 MERGE INTO mv t
diff --git a/src/test/regress/sql/rules.sql b/src/test/regress/sql/rules.sql
new file mode 100644
index 93aff4e..6924012
--- a/src/test/regress/sql/rules.sql
+++ b/src/test/regress/sql/rules.sql
@@ -1277,6 +1277,19 @@ MERGE INTO rule_merge2 t USING (SELECT 1
 	WHEN NOT MATCHED THEN
 		INSERT VALUES (s.a, '');
 
+-- also ok if the rules are disabled
+ALTER TABLE rule_merge1 DISABLE RULE rule1;
+ALTER TABLE rule_merge1 DISABLE RULE rule2;
+ALTER TABLE rule_merge1 DISABLE RULE rule3;
+MERGE INTO rule_merge1 t USING (SELECT 1 AS a) s
+	ON t.a = s.a
+	WHEN MATCHED AND t.a < 2 THEN
+		UPDATE SET b = b || ' updated by merge'
+	WHEN MATCHED AND t.a > 2 THEN
+		DELETE
+	WHEN NOT MATCHED THEN
+		INSERT VALUES (s.a, '');
+
 -- test deparsing
 CREATE TABLE sf_target(id int, data text, filling int[]);
 
diff --git a/src/test/regress/sql/updatable_views.sql b/src/test/regress/sql/updatable_views.sql
new file mode 100644
index eaee0b7..ae11e46
--- a/src/test/regress/sql/updatable_views.sql
+++ b/src/test/regress/sql/updatable_views.sql
@@ -62,6 +62,15 @@ UPDATE ro_view10 SET a=a+1;
 UPDATE ro_view11 SET a=a+1;
 UPDATE ro_view12 SET a=a+1;
 INSERT INTO ro_view13 VALUES (3, 'Row 3');
+MERGE INTO ro_view13 AS t USING (VALUES (1, 'Row 1')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+MERGE INTO ro_view13 AS t USING (VALUES (2, 'Row 2')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b;
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b);
+MERGE INTO ro_view13 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DO NOTHING
+  WHEN NOT MATCHED THEN DO NOTHING; -- should be OK to do nothing
 -- Partially updatable view
 INSERT INTO rw_view14 VALUES (null, 3, 'Row 3'); -- should fail
 INSERT INTO rw_view14 (a, b) VALUES (3, 'Row 3'); -- should be OK
@@ -69,6 +78,20 @@ UPDATE rw_view14 SET ctid=null WHERE a=3
 UPDATE rw_view14 SET b='ROW 3' WHERE a=3; -- should be OK
 SELECT * FROM base_tbl;
 DELETE FROM rw_view14 WHERE a=3; -- should be OK
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK, except...
+  WHEN NOT MATCHED THEN INSERT VALUES (null, v.a, v.b); -- should fail
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Merged row 2'), (3, 'Merged row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = v.b  -- should be OK
+  WHEN NOT MATCHED THEN INSERT (a,b) VALUES (v.a, v.b); -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
+MERGE INTO rw_view14  AS t
+  USING (VALUES (2, 'Row 2'), (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a = 2 THEN UPDATE SET b = v.b  -- should be OK
+  WHEN MATCHED AND t.a = 3 THEN DELETE; -- should be OK
+SELECT * FROM base_tbl ORDER BY a;
 -- Partially updatable view
 INSERT INTO rw_view15 VALUES (3, 'ROW 3'); -- should fail
 INSERT INTO rw_view15 (a) VALUES (3); -- should be OK
@@ -114,6 +137,8 @@ CREATE RULE rw_view16_del_rule AS ON DEL
 INSERT INTO rw_view16 (a, b) VALUES (3, 'Row 3'); -- should fail
 UPDATE rw_view16 SET b='ROW 2' WHERE a=2; -- should fail
 DELETE FROM rw_view16 WHERE a=2; -- should fail
+MERGE INTO rw_view16 AS t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
 
 DROP TABLE base_tbl CASCADE;
 DROP VIEW ro_view10, ro_view12, ro_view18;
@@ -145,9 +170,31 @@ UPDATE rw_view1 SET a=5 WHERE a=4;
 DELETE FROM rw_view1 WHERE b='Row 2';
 SELECT * FROM base_tbl;
 
+MERGE INTO rw_view1 t
+  USING (VALUES (0, 'ROW 0'), (1, 'ROW 1'),
+                (2, 'ROW 2'), (3, 'ROW 3')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED AND t.a <= 1 THEN UPDATE SET b = v.b
+  WHEN MATCHED THEN DELETE
+  WHEN NOT MATCHED AND a > 0 THEN INSERT (a) VALUES (v.a);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t USING (VALUES (5, 'X')) AS v(a,b) ON t.a = v.a
+  WHEN MATCHED THEN DELETE;
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = 'Updated';
+
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (SELECT * FROM generate_series(1,5)) AS s(a) ON t.a = s.a
+  WHEN NOT MATCHED THEN INSERT (a) VALUES (s.a);
+
 -- it's still updatable if we add a DO ALSO rule
 
 CREATE TABLE base_tbl_hist(ts timestamptz default now(), a int, b text);
@@ -195,6 +242,13 @@ UPDATE rw_view2 SET bbb='Row 4' WHERE aa
 DELETE FROM rw_view2 WHERE aaa=2;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (VALUES (3, 'R3'), (4, 'R4'), (5, 'R5')) AS v(a,b) ON aaa = v.a
+  WHEN MATCHED AND aaa = 3 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET bbb = v.b
+  WHEN NOT MATCHED THEN INSERT (aaa) VALUES (v.a);
+SELECT * FROM rw_view2 ORDER BY aaa;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
 
@@ -283,6 +337,9 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t USING (VALUES (3, 'Row 3')) AS v(a,b) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.b); -- should fail
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
@@ -397,9 +454,56 @@ SELECT * FROM rw_view2;
 DELETE FROM rw_view2 WHERE a=3 RETURNING *;
 SELECT * FROM rw_view2;
 
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+SELECT * FROM base_tbl ORDER BY a;
+
 EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
 
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b);
+
+-- MERGE with incomplete set of INSTEAD OF triggers
+DROP TRIGGER rw_view1_del_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED AND t.a <= 1 THEN DELETE
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- ok
+
+DROP TRIGGER rw_view1_ins_trig ON rw_view1;
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+
+-- MERGE with INSTEAD OF triggers on auto-updatable view
+CREATE TRIGGER rw_view2_upd_trig INSTEAD OF UPDATE ON rw_view2
+  FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b
+  WHEN NOT MATCHED AND s.a > 0 THEN INSERT VALUES (s.a, s.b); -- should fail
+MERGE INTO rw_view2 t
+  USING (SELECT x, 'R'||x FROM generate_series(0,3) x) AS s(a,b) ON t.a = s.a
+  WHEN MATCHED THEN UPDATE SET b = s.b; -- ok
+SELECT * FROM base_tbl ORDER BY a;
+
 DROP TABLE base_tbl CASCADE;
 DROP FUNCTION rw_view1_trig_fn();
 
@@ -451,6 +555,13 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
 
+MERGE INTO rw_view1 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+MERGE INTO rw_view2 t
+  USING (VALUES ('Row 3', 3.0, 3)) AS v(b,c,a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
+
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
@@ -458,6 +569,15 @@ UPDATE rw_view1 SET aa=aa; -- not allowe
 UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
 UPDATE rw_view2 SET bb=bb; -- not allowed
 
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb, cc = cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, cc = cc; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
+
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
 DELETE FROM rw_view2; -- not allowed
@@ -474,6 +594,10 @@ INSERT INTO rw_view2 VALUES ('Row 4', 4.
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
 DELETE FROM rw_view2 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -489,6 +613,10 @@ INSERT INTO rw_view2 VALUES ('Row 6', 6.
 DELETE FROM base_tbl WHERE a=3; -- not allowed
 DELETE FROM rw_view1 WHERE aa=3; -- ok
 DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED AND bb = 'xxx' THEN DELETE; -- not allowed
 SELECT * FROM base_tbl;
 RESET SESSION AUTHORIZATION;
 
@@ -504,12 +632,16 @@ CREATE VIEW rw_view1 AS SELECT * FROM ba
 SELECT * FROM rw_view1;  -- not allowed
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT * FROM rw_view1;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT SELECT ON base_tbl TO regress_view_user1;
@@ -518,11 +650,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -531,6 +667,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 GRANT UPDATE ON base_tbl TO regress_view_user1;
@@ -539,11 +677,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo';
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'bar'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT UPDATE ON rw_view1 TO regress_view_user2;
@@ -552,6 +694,8 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'fud';
 
 RESET SESSION AUTHORIZATION;
 REVOKE UPDATE ON base_tbl FROM regress_view_user1;
@@ -560,11 +704,15 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1;
 SELECT * FROM rw_view1 FOR UPDATE;  -- not allowed
 UPDATE rw_view1 SET b = 'foo' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;
 SELECT * FROM rw_view2 FOR UPDATE;  -- not allowed
 UPDATE rw_view2 SET b = 'bar' WHERE a = 1;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET b = 'foo'; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -588,8 +736,12 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
 UPDATE base_tbl SET a=a; -- not allowed
 UPDATE rw_view1 SET bb=bb, cc=cc; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 DELETE FROM base_tbl; -- not allowed
 DELETE FROM rw_view1; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON base_tbl TO regress_view_user2;
@@ -601,8 +753,14 @@ SELECT * FROM rw_view1; -- ok
 UPDATE base_tbl SET a=a, c=c; -- ok
 UPDATE base_tbl SET b=b; -- not allowed
 UPDATE rw_view1 SET cc=cc; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- ok
 UPDATE rw_view1 SET aa=aa; -- not allowed
 UPDATE rw_view1 SET bb=bb; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET bb = bb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -612,6 +770,8 @@ INSERT INTO base_tbl VALUES (3, 'Row 3',
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM base_tbl WHERE a=1; -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 REVOKE INSERT, DELETE ON base_tbl FROM regress_view_user2;
@@ -620,6 +780,8 @@ GRANT INSERT, DELETE ON rw_view1 TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
 DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT INSERT, DELETE ON base_tbl TO regress_view_user2;
@@ -627,6 +789,8 @@ GRANT INSERT, DELETE ON base_tbl TO regr
 SET SESSION AUTHORIZATION regress_view_user2;
 INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- ok
 DELETE FROM rw_view1 WHERE aa=2; -- ok
+MERGE INTO rw_view1 t USING (VALUES (3)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN DELETE; -- ok
 SELECT * FROM base_tbl; -- ok
 
 RESET SESSION AUTHORIZATION;
@@ -643,12 +807,16 @@ CREATE VIEW rw_view1 AS SELECT b AS bb,
 ALTER VIEW rw_view1 SET (security_invoker = true);
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.b, v.c, v.a); -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 CREATE VIEW rw_view2 AS SELECT cc AS ccc, aa AS aaa, bb AS bbb FROM rw_view1;
 GRANT SELECT, UPDATE ON rw_view2 TO regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (2, 'Row 2', 2.0)) AS v(a,b,c) ON t.aaa = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.c, v.a, v.b); -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -659,14 +827,22 @@ SET SESSION AUTHORIZATION regress_view_u
 SELECT * FROM rw_view1; -- ok
 UPDATE rw_view1 SET aa=aa, bb=bb;  -- ok
 UPDATE rw_view1 SET cc=cc;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa, bb = bb; -- ok
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET cc = cc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user1;
 GRANT SELECT ON rw_view1 TO regress_view_user2;
@@ -675,10 +851,14 @@ GRANT UPDATE (bb, cc) ON rw_view1 TO reg
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -690,12 +870,24 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 RESET SESSION AUTHORIZATION;
 
@@ -707,6 +899,12 @@ SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -715,18 +913,32 @@ REVOKE SELECT, UPDATE ON base_tbl FROM r
 SET SESSION AUTHORIZATION regress_view_user1;
 SELECT * FROM rw_view1;  -- not allowed
 UPDATE rw_view1 SET aa=aa;  -- not allowed
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.aa = v.a
+  WHEN MATCHED THEN UPDATE SET aa = aa; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user2;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -737,12 +949,24 @@ SELECT * FROM rw_view2;  -- not allowed
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- not allowed
 
 SET SESSION AUTHORIZATION regress_view_user3;
 SELECT * FROM rw_view2;  -- ok
 UPDATE rw_view2 SET aaa=aaa;  -- not allowed
 UPDATE rw_view2 SET bbb=bbb;  -- not allowed
 UPDATE rw_view2 SET ccc=ccc;  -- ok
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET aaa = aaa; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET bbb = bbb; -- not allowed
+MERGE INTO rw_view2 t USING (VALUES (1)) AS v(a) ON t.aaa = v.a
+  WHEN MATCHED THEN UPDATE SET ccc = ccc; -- ok
 
 RESET SESSION AUTHORIZATION;
 
@@ -764,6 +988,8 @@ ALTER VIEW rw_view1 ALTER COLUMN bb SET
 
 INSERT INTO rw_view1 VALUES (4, 'Row 4');
 INSERT INTO rw_view1 (aa) VALUES (5);
+MERGE INTO rw_view1 t USING (VALUES (6)) AS v(a) ON t.aa = v.a
+  WHEN NOT MATCHED THEN INSERT (aa) VALUES (v.a);
 
 SELECT * FROM base_tbl;
 
@@ -945,6 +1171,18 @@ DELETE FROM ONLY rw_view2 WHERE a IN (-8
 SELECT * FROM ONLY base_tbl_parent ORDER BY a;
 SELECT * FROM base_tbl_child ORDER BY a;
 
+MERGE INTO rw_view1 t USING (VALUES (-200), (10)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -199 and 11
+MERGE INTO ONLY rw_view1 t USING (VALUES (-100), (20)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -99 and 21
+MERGE INTO rw_view2 t USING (VALUES (-40), (3)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -39 only
+MERGE INTO ONLY rw_view2 t USING (VALUES (-30), (4)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a+1; -- Should produce -29 only
+
+SELECT * FROM ONLY base_tbl_parent ORDER BY a;
+SELECT * FROM base_tbl_child ORDER BY a;
+
 CREATE TABLE other_tbl_parent (id int);
 CREATE TABLE other_tbl_child () INHERITS (other_tbl_parent);
 INSERT INTO other_tbl_parent VALUES (7),(200);
@@ -977,7 +1215,17 @@ UPDATE rw_view1 SET b = 5 WHERE a = 3; -
 UPDATE rw_view1 SET b = -5 WHERE a = 3; -- should fail
 INSERT INTO rw_view1(a) VALUES (9); -- ok
 INSERT INTO rw_view1(a) VALUES (10); -- should fail
-SELECT * FROM base_tbl;
+SELECT * FROM base_tbl ORDER BY a, b;
+
+MERGE INTO rw_view1 t USING (VALUES (10)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a + 1); -- ok
+MERGE INTO rw_view1 t USING (VALUES (11)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a, v.a - 1); -- should fail
+MERGE INTO rw_view1 t USING (VALUES (1)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 1; -- ok
+MERGE INTO rw_view1 t USING (VALUES (2)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a + 1; -- should fail
+SELECT * FROM base_tbl ORDER BY a, b;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1139,9 +1387,17 @@ CREATE VIEW rw_view2 AS
   SELECT * FROM rw_view1 WHERE a > 0 WITH LOCAL CHECK OPTION;
 
 INSERT INTO rw_view2 VALUES (-5); -- should fail
+MERGE INTO rw_view2 t USING (VALUES (-5)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- should fail
 INSERT INTO rw_view2 VALUES (5); -- ok
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok
 INSERT INTO rw_view2 VALUES (50); -- ok, but not in view
+MERGE INTO rw_view2 t USING (VALUES (60)) AS v(a) ON t.a = v.a
+  WHEN NOT MATCHED THEN INSERT VALUES (v.a); -- ok, but not in view
 UPDATE rw_view2 SET a = a - 10; -- should fail
+MERGE INTO rw_view2 t USING (VALUES (6)) AS v(a) ON t.a = v.a
+  WHEN MATCHED THEN UPDATE SET a = t.a - 10; -- should fail
 SELECT * FROM base_tbl;
 
 -- Check option won't cascade down to base view with INSTEAD OF triggers
@@ -1229,10 +1485,17 @@ SELECT table_name, column_name, is_updat
 SELECT * FROM rw_view1 WHERE snoop(person);
 UPDATE rw_view1 SET person=person WHERE snoop(person);
 DELETE FROM rw_view1 WHERE NOT snoop(person);
+MERGE INTO rw_view1 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
 
 EXPLAIN (costs off) SELECT * FROM rw_view1 WHERE snoop(person);
 EXPLAIN (costs off) UPDATE rw_view1 SET person=person WHERE snoop(person);
 EXPLAIN (costs off) DELETE FROM rw_view1 WHERE NOT snoop(person);
+EXPLAIN (costs off)
+MERGE INTO rw_view1 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
 
 -- security barrier view on top of security barrier view
 
@@ -1255,10 +1518,17 @@ SELECT table_name, column_name, is_updat
 SELECT * FROM rw_view2 WHERE snoop(person);
 UPDATE rw_view2 SET person=person WHERE snoop(person);
 DELETE FROM rw_view2 WHERE NOT snoop(person);
+MERGE INTO rw_view2 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
 
 EXPLAIN (costs off) SELECT * FROM rw_view2 WHERE snoop(person);
 EXPLAIN (costs off) UPDATE rw_view2 SET person=person WHERE snoop(person);
 EXPLAIN (costs off) DELETE FROM rw_view2 WHERE NOT snoop(person);
+EXPLAIN (costs off)
+MERGE INTO rw_view2 t
+  USING (VALUES ('Tom'), ('Dick'), ('Harry')) AS v(person) ON t.person = v.person
+  WHEN MATCHED AND snoop(t.person) THEN UPDATE SET person = v.person;
 
 DROP TABLE base_tbl CASCADE;
 
@@ -1480,6 +1750,19 @@ insert into uv_ptv values (1, 2);
 select tableoid::regclass, * from uv_pt;
 create view uv_ptv_wco as select * from uv_pt where a = 0 with check option;
 insert into uv_ptv_wco values (1, 2);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a -- fail: matches 2 src rows
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1);
+merge into uv_ptv t
+  using (values (1,2), (1,4)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- fail: no partition for b=5
+merge into uv_ptv t
+  using (values (1,2), (1,3)) as v(a,b) on t.a = v.a and t.b = v.b
+  when matched then update set b = t.b + 1
+  when not matched then insert values (v.a, v.b + 1); -- ok
+select tableoid::regclass, * from uv_pt order by a, b;
 drop view uv_ptv, uv_ptv_wco;
 drop table uv_pt, uv_pt1, uv_pt11;