COPY with hints, rebirth

diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml
index a73b022..4912449 100644
--- a/doc/src/sgml/ref/copy.sgml
+++ b/doc/src/sgml/ref/copy.sgml
@@ -34,6 +34,7 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable
 
     FORMAT <replaceable class="parameter">format_name</replaceable>
     OIDS [ <replaceable class="parameter">boolean</replaceable> ]
+    FREEZE [ <replaceable class="parameter">boolean</replaceable> ]
     DELIMITER '<replaceable class="parameter">delimiter_character</replaceable>'
     NULL '<replaceable class="parameter">null_string</replaceable>'
     HEADER [ <replaceable class="parameter">boolean</replaceable> ]
@@ -181,6 +182,23 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable
    </varlistentry>
 
    <varlistentry>
+    <term><literal>FREEZE</literal></term>
+    <listitem>
+     <para>
+      Specifies copying the data with rows already frozen, just as they
+      would be after running the <command>VACUUM FREEZE</> command.
+      This only occurs if the table being loaded has been created in this
+      subtransaction, there are no cursors open and there are no older
+      snapshots held by this transaction.
+      Note that all sessions will immediately be able to see the data
+      if it has been successfully loaded, which specifically operates
+      outside of the normal definitions of MVCC. This is a performance
+      option intended for use only during initial data loads.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
     <term><literal>DELIMITER</literal></term>
     <listitem>
      <para>
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..68534bf 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2050,7 +2050,13 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
 	tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
 	tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
 	tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
-	HeapTupleHeaderSetXmin(tup->t_data, xid);
+	if (options & HEAP_INSERT_FREEZE)
+	{
+		HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId);
+		tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+	}
+	else
+		HeapTupleHeaderSetXmin(tup->t_data, xid);
 	HeapTupleHeaderSetCmin(tup->t_data, cid);
 	HeapTupleHeaderSetXmax(tup->t_data, 0);		/* for cleanliness */
 	tup->t_tableOid = RelationGetRelid(relation);
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 110480f..ec0bed8 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -43,6 +43,7 @@
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/portal.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 
@@ -108,6 +109,7 @@ typedef struct CopyStateData
 	char	   *filename;		/* filename, or NULL for STDIN/STDOUT */
 	bool		binary;			/* binary format? */
 	bool		oids;			/* include OIDs? */
+	bool		freeze;			/* freeze rows on loading? */
 	bool		csv_mode;		/* Comma Separated Value format? */
 	bool		header_line;	/* CSV header line? */
 	char	   *null_print;		/* NULL marker string (server encoding!) */
@@ -889,6 +891,14 @@ ProcessCopyOptions(CopyState cstate,
 						 errmsg("conflicting or redundant options")));
 			cstate->oids = defGetBoolean(defel);
 		}
+		else if (strcmp(defel->defname, "freeze") == 0)
+		{
+			if (cstate->freeze)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			cstate->freeze = defGetBoolean(defel);
+		}
 		else if (strcmp(defel->defname, "delimiter") == 0)
 		{
 			if (cstate->delim)
@@ -1922,6 +1932,11 @@ CopyFrom(CopyState cstate)
 		hi_options |= HEAP_INSERT_SKIP_FSM;
 		if (!XLogIsNeeded())
 			hi_options |= HEAP_INSERT_SKIP_WAL;
+
+		if (cstate->freeze &&
+			ThereAreNoPriorRegisteredSnapshots() &&
+			ThereAreNoReadyPortals())
+			hi_options |= HEAP_INSERT_FREEZE;
 	}
 
 	/*
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d1ce2ab..cd2b243 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2315,6 +2315,10 @@ copy_opt_item:
 				{
 					$$ = makeDefElem("oids", (Node *)makeInteger(TRUE));
 				}
+			| FREEZE
+				{
+					$$ = makeDefElem("freeze", (Node *)makeInteger(TRUE));
+				}
 			| DELIMITER opt_as Sconst
 				{
 					$$ = makeDefElem("delimiter", (Node *)makeString($3));
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index cfb73c1..24075db 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS)
 
 	return (Datum) 0;
 }
+
+bool
+ThereAreNoReadyPortals(void)
+{
+	HASH_SEQ_STATUS status;
+	PortalHashEnt *hentry;
+
+	hash_seq_init(&status, PortalHashTable);
+
+	while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+	{
+		Portal		portal = hentry->portal;
+
+		if (portal->status == PORTAL_READY)
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 5aebbd1..5d9e3bf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void)
 
 	FreeDir(s_dir);
 }
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+	if (RegisteredSnapshots <= 1)
+		return true;
+
+	return false;
+}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index fa38803..61472f2 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -26,6 +26,7 @@
 /* "options" flag bits for heap_insert */
 #define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
+#define HEAP_INSERT_FREEZE		0x0004
 
 typedef struct BulkInsertStateData *BulkInsertState;
 
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 4833942..bd2b133 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal,
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
 
 #endif   /* PORTAL_H */
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index f195981..789b72e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS);
 extern void ImportSnapshot(const char *idstr);
 extern bool XactHasExportedSnapshots(void);
 extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
 
 #endif   /* SNAPMGR_H */
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 8e2bc0c..ad2c24c 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -239,6 +239,53 @@ a\.
 \.b
 c\.d
 "\."
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+COMMIT;
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+COMMIT;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 6322c8f..4da6452 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -164,6 +164,43 @@ c\.d
 
 COPY testeoc TO stdout CSV;
 
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+COMMIT;
+
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV FREEZE;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+COMMIT;
+
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..3899282 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2056,6 +2056,17 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
 	tup->t_tableOid = RelationGetRelid(relation);
 
 	/*
+	 * If we are inserting into a new relation invisible as yet to other
+	 * backends and our session has no prior snapshots and no ready portals
+	 * then we can also set the hint bit for the rows we are inserting. The
+	 * last two restrictions ensure that HeapTupleSatisfiesMVCC() gives
+	 * the right answer if the current transaction inspects the data after
+	 * we load it.
+	 */
+	if (options & HEAP_INSERT_HINT_XMIN)
+		tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+
+	/*
 	 * If the new tuple is too big for storage or contains already toasted
 	 * out-of-line attributes from some other relation, invoke the toaster.
 	 */
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index e22bdac..de7504c 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -146,6 +146,7 @@ typedef struct TransactionStateData
 	int			prevSecContext; /* previous SecurityRestrictionContext */
 	bool		prevXactReadOnly;		/* entry-time xact r/o state */
 	bool		startedInRecovery;		/* did we start in recovery? */
+	bool		maySeePreHintedTuples;	/* did subtrans write pre-hinted rows? */
 	struct TransactionStateData *parent;		/* back link to parent */
 } TransactionStateData;
 
@@ -175,6 +176,7 @@ static TransactionStateData TopTransactionStateData = {
 	0,							/* previous SecurityRestrictionContext */
 	false,						/* entry-time xact r/o state */
 	false,						/* startedInRecovery */
+	false,						/* maySeePreHintedTuples */
 	NULL						/* link to parent state block */
 };
 
@@ -704,6 +706,18 @@ TransactionStartedDuringRecovery(void)
 	return CurrentTransactionState->startedInRecovery;
 }
 
+bool
+TransactionMaySeePreHintedTuples(void)
+{
+	return CurrentTransactionState->maySeePreHintedTuples;
+}
+
+void
+TransactionMayWritePreHintedTuples(void)
+{
+	CurrentTransactionState->maySeePreHintedTuples = true;
+}
+
 /*
  *	CommandCounterIncrement
  */
@@ -1689,6 +1703,7 @@ StartTransaction(void)
 		s->startedInRecovery = false;
 		XactReadOnly = DefaultXactReadOnly;
 	}
+	s->maySeePreHintedTuples = false;
 	XactDeferrable = DefaultXactDeferrable;
 	XactIsoLevel = DefaultXactIsoLevel;
 	forceSyncCommit = false;
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 110480f..1419e33 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -43,6 +43,7 @@
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/portal.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 
@@ -1922,6 +1923,13 @@ CopyFrom(CopyState cstate)
 		hi_options |= HEAP_INSERT_SKIP_FSM;
 		if (!XLogIsNeeded())
 			hi_options |= HEAP_INSERT_SKIP_WAL;
+
+		if (ThereAreNoPriorRegisteredSnapshots() &&
+			ThereAreNoReadyPortals())
+		{
+			hi_options |= HEAP_INSERT_HINT_XMIN;
+			TransactionMayWritePreHintedTuples();
+		}
 	}
 
 	/*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index cfb73c1..24075db 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS)
 
 	return (Datum) 0;
 }
+
+bool
+ThereAreNoReadyPortals(void)
+{
+	HASH_SEQ_STATUS status;
+	PortalHashEnt *hentry;
+
+	hash_seq_init(&status, PortalHashTable);
+
+	while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+	{
+		Portal		portal = hentry->portal;
+
+		if (portal->status == PORTAL_READY)
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 5aebbd1..5d9e3bf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void)
 
 	FreeDir(s_dir);
 }
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+	if (RegisteredSnapshots <= 1)
+		return true;
+
+	return false;
+}
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index 31791a7..6cb4152 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -1255,6 +1255,28 @@ XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot)
 	/* Any xid < xmin is not in-progress */
 	if (TransactionIdPrecedes(xid, snapshot->xmin))
 		return false;
+
+	/*
+	 * TransactionIdIsCurrentTransactionId() could be expensive so avoid
+	 * running it unless we know that the current subtransaction has
+	 * decided to write tuples that already have HEAP_XMIN_COMMITTED set.
+	 * In that case we end up here when we run HeapTupleSatisfiesMVCC.
+	 */
+	if (TransactionMaySeePreHintedTuples())
+	{
+		/*
+		 * Make sure current xid is never thought to be in progress on tuples
+		 * that are already marked as committed - for use in bulk COPY etc..
+		 * We never included the current xid in snapshots, but its possible
+		 * that the current xid is equal to or greater than xmax, so we
+		 * check for the current xid before we check for xmax.
+		 * We could optimise this further by stopping the search as soon
+		 * as the xid is less than xmax, but seems like a step too far.
+		 */
+		if (TransactionIdIsCurrentTransactionId(xid))
+			return false;
+	}
+
 	/* Any xid >= xmax is in-progress */
 	if (TransactionIdFollowsOrEquals(xid, snapshot->xmax))
 		return true;
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index fa38803..0381785 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -26,6 +26,7 @@
 /* "options" flag bits for heap_insert */
 #define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
+#define HEAP_INSERT_HINT_XMIN	0x0004
 
 typedef struct BulkInsertStateData *BulkInsertState;
 
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 20e344e..7fb0123 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -217,6 +217,8 @@ extern TimestampTz GetCurrentTransactionStopTimestamp(void);
 extern void SetCurrentStatementStartTimestamp(void);
 extern int	GetCurrentTransactionNestLevel(void);
 extern bool TransactionIdIsCurrentTransactionId(TransactionId xid);
+extern bool TransactionMaySeePreHintedTuples(void);
+extern void TransactionMayWritePreHintedTuples(void);
 extern void CommandCounterIncrement(void);
 extern void ForceSyncCommit(void);
 extern void StartTransactionCommand(void);
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 4833942..bd2b133 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal,
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
 
 #endif   /* PORTAL_H */
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index f195981..789b72e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS);
 extern void ImportSnapshot(const char *idstr);
 extern bool XactHasExportedSnapshots(void);
 extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
 
 #endif   /* SNAPMGR_H */
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 8e2bc0c..7461529 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -239,6 +239,49 @@ a\.
 \.b
 c\.d
 "\."
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+SAVEPOINT s2;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+COMMIT;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 6322c8f..a1a8d97 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -164,6 +164,34 @@ c\.d
 
 COPY testeoc TO stdout CSV;
 
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+SAVEPOINT s2;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+x
+y
+z
+\.
+SELECT * FROM vistest;
+COMMIT;
+SELECT * FROM vistest;
+
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..b891327 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2050,12 +2050,27 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
 	tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
 	tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
 	tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
-	HeapTupleHeaderSetXmin(tup->t_data, xid);
 	HeapTupleHeaderSetCmin(tup->t_data, cid);
 	HeapTupleHeaderSetXmax(tup->t_data, 0);		/* for cleanliness */
 	tup->t_tableOid = RelationGetRelid(relation);
 
 	/*
+	 * If we are inserting into a new relation invisible as yet to other
+	 * backends and our session has no prior snapshots and no ready portals
+	 * then we can also set the hint bit for the rows we are inserting. The
+	 * last two restrictions ensure that HeapTupleSatisfiesMVCC() gives
+	 * the right answer if the current transaction inspects the data after
+	 * we load it.
+	 */
+	if (options & HEAP_INSERT_HINT_XMIN)
+	{
+		tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+		HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId);
+	}
+	else
+		HeapTupleHeaderSetXmin(tup->t_data, xid);
+
+	/*
 	 * If the new tuple is too big for storage or contains already toasted
 	 * out-of-line attributes from some other relation, invoke the toaster.
 	 */
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 110480f..a34f072 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -43,6 +43,7 @@
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/portal.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 
@@ -1922,6 +1923,21 @@ CopyFrom(CopyState cstate)
 		hi_options |= HEAP_INSERT_SKIP_FSM;
 		if (!XLogIsNeeded())
 			hi_options |= HEAP_INSERT_SKIP_WAL;
+
+		if (ThereAreNoPriorRegisteredSnapshots() &&
+			ThereAreNoReadyPortals())
+		{
+			SubTransactionId	currxid = GetCurrentSubTransactionId();
+
+			/*
+			 * If the relfilenode has been created in this subtransaction
+			 * then we can further optimise the data load by setting hint
+			 * bits and pre-freezing tuples.
+			 */
+			if (cstate->rel->rd_createSubid == currxid ||
+				cstate->rel->rd_newRelfilenodeSubid == currxid)
+				hi_options |= HEAP_INSERT_HINT_XMIN;
+		}
 	}
 
 	/*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index cfb73c1..24075db 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS)
 
 	return (Datum) 0;
 }
+
+bool
+ThereAreNoReadyPortals(void)
+{
+	HASH_SEQ_STATUS status;
+	PortalHashEnt *hentry;
+
+	hash_seq_init(&status, PortalHashTable);
+
+	while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+	{
+		Portal		portal = hentry->portal;
+
+		if (portal->status == PORTAL_READY)
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 5aebbd1..5d9e3bf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void)
 
 	FreeDir(s_dir);
 }
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+	if (RegisteredSnapshots <= 1)
+		return true;
+
+	return false;
+}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index fa38803..0381785 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -26,6 +26,7 @@
 /* "options" flag bits for heap_insert */
 #define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
+#define HEAP_INSERT_HINT_XMIN	0x0004
 
 typedef struct BulkInsertStateData *BulkInsertState;
 
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 4833942..bd2b133 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal,
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
 
 #endif   /* PORTAL_H */
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index f195981..789b72e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS);
 extern void ImportSnapshot(const char *idstr);
 extern bool XactHasExportedSnapshots(void);
 extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
 
 #endif   /* SNAPMGR_H */
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 8e2bc0c..b9626e5 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -239,6 +239,70 @@ a\.
 \.b
 c\.d
 "\."
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ j
+ k
+ l
+(3 rows)
+
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+COMMIT;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 6322c8f..3d2c376 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -164,6 +164,45 @@ c\.d
 
 COPY testeoc TO stdout CSV;
 
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+j
+k
+l
+\.
+SELECT * FROM vistest;
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+x
+y
+z
+\.
+SELECT * FROM vistest;
+COMMIT;
+SELECT * FROM vistest;
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..b891327 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2050,12 +2050,27 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
 	tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
 	tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
 	tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
-	HeapTupleHeaderSetXmin(tup->t_data, xid);
 	HeapTupleHeaderSetCmin(tup->t_data, cid);
 	HeapTupleHeaderSetXmax(tup->t_data, 0);		/* for cleanliness */
 	tup->t_tableOid = RelationGetRelid(relation);
 
 	/*
+	 * If we are inserting into a new relation invisible as yet to other
+	 * backends and our session has no prior snapshots and no ready portals
+	 * then we can also set the hint bit for the rows we are inserting. The
+	 * last two restrictions ensure that HeapTupleSatisfiesMVCC() gives
+	 * the right answer if the current transaction inspects the data after
+	 * we load it.
+	 */
+	if (options & HEAP_INSERT_HINT_XMIN)
+	{
+		tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+		HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId);
+	}
+	else
+		HeapTupleHeaderSetXmin(tup->t_data, xid);
+
+	/*
 	 * If the new tuple is too big for storage or contains already toasted
 	 * out-of-line attributes from some other relation, invoke the toaster.
 	 */
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 110480f..a34f072 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -43,6 +43,7 @@
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/portal.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 
@@ -1922,6 +1923,21 @@ CopyFrom(CopyState cstate)
 		hi_options |= HEAP_INSERT_SKIP_FSM;
 		if (!XLogIsNeeded())
 			hi_options |= HEAP_INSERT_SKIP_WAL;
+
+		if (ThereAreNoPriorRegisteredSnapshots() &&
+			ThereAreNoReadyPortals())
+		{
+			SubTransactionId	currxid = GetCurrentSubTransactionId();
+
+			/*
+			 * If the relfilenode has been created in this subtransaction
+			 * then we can further optimise the data load by setting hint
+			 * bits and pre-freezing tuples.
+			 */
+			if (cstate->rel->rd_createSubid == currxid ||
+				cstate->rel->rd_newRelfilenodeSubid == currxid)
+				hi_options |= HEAP_INSERT_HINT_XMIN;
+		}
 	}
 
 	/*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index cfb73c1..24075db 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS)
 
 	return (Datum) 0;
 }
+
+bool
+ThereAreNoReadyPortals(void)
+{
+	HASH_SEQ_STATUS status;
+	PortalHashEnt *hentry;
+
+	hash_seq_init(&status, PortalHashTable);
+
+	while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+	{
+		Portal		portal = hentry->portal;
+
+		if (portal->status == PORTAL_READY)
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 5aebbd1..5d9e3bf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void)
 
 	FreeDir(s_dir);
 }
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+	if (RegisteredSnapshots <= 1)
+		return true;
+
+	return false;
+}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index fa38803..0381785 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -26,6 +26,7 @@
 /* "options" flag bits for heap_insert */
 #define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
+#define HEAP_INSERT_HINT_XMIN	0x0004
 
 typedef struct BulkInsertStateData *BulkInsertState;
 
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 4833942..bd2b133 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal,
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
 
 #endif   /* PORTAL_H */
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index f195981..789b72e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS);
 extern void ImportSnapshot(const char *idstr);
 extern bool XactHasExportedSnapshots(void);
 extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
 
 #endif   /* SNAPMGR_H */
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 8e2bc0c..b9626e5 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -239,6 +239,70 @@ a\.
 \.b
 c\.d
 "\."
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ j
+ k
+ l
+(3 rows)
+
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+COMMIT;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 6322c8f..3d2c376 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -164,6 +164,45 @@ c\.d
 
 COPY testeoc TO stdout CSV;
 
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+j
+k
+l
+\.
+SELECT * FROM vistest;
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+x
+y
+z
+\.
+SELECT * FROM vistest;
+COMMIT;
+SELECT * FROM vistest;
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..4387f49 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -73,7 +73,7 @@
 
 /* GUC variable */
 bool		synchronize_seqscans = true;
-
+bool		StrictMVCC = true;
 
 static HeapScanDesc heap_beginscan_internal(Relation relation,
 						Snapshot snapshot,
@@ -1175,6 +1175,24 @@ heap_beginscan_internal(Relation relation, Snapshot snapshot,
 	HeapScanDesc scan;
 
 	/*
+	 * If the snapshot is older than relvalidxmin then that either a table
+	 * has only recently been created or that a TRUNCATE has removed data
+	 * that we should still be able to see. Either way, we aren't allowed
+	 * to view the rows in StrictMVCC mode.
+	 */
+	if (StrictMVCC &&
+		TransactionIdIsValid(relation->rd_rel->relvalidxmin) &&
+		TransactionIdIsValid(snapshot->xmax) &&
+		NormalTransactionIdPrecedes(snapshot->xmax, relation->rd_rel->relvalidxmin))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+				 errmsg("canceling statement due to conflict with TRUNCATE TABLE on %s",
+						 NameStr(relation->rd_rel->relname)),
+				 errdetail("User query attempting to see row versions that have been removed.")));
+	}
+
+	/*
 	 * increment relation ref count while scanning relation
 	 *
 	 * This is just to make really sure the relcache entry won't go away while
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index aef410a..3f9bd5d 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -787,6 +787,7 @@ InsertPgClassTuple(Relation pg_class_desc,
 	values[Anum_pg_class_relhastriggers - 1] = BoolGetDatum(rd_rel->relhastriggers);
 	values[Anum_pg_class_relhassubclass - 1] = BoolGetDatum(rd_rel->relhassubclass);
 	values[Anum_pg_class_relfrozenxid - 1] = TransactionIdGetDatum(rd_rel->relfrozenxid);
+	values[Anum_pg_class_relvalidxmin - 1] = TransactionIdGetDatum(rd_rel->relvalidxmin);
 	if (relacl != (Datum) 0)
 		values[Anum_pg_class_relacl - 1] = relacl;
 	else
@@ -884,6 +885,7 @@ AddNewRelationTuple(Relation pg_class_desc,
 		new_rel_reltup->relfrozenxid = InvalidTransactionId;
 	}
 
+	new_rel_reltup->relvalidxmin = InvalidTransactionId;
 	new_rel_reltup->relowner = relowner;
 	new_rel_reltup->reltype = new_type_oid;
 	new_rel_reltup->reloftype = reloftype;
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index bfbe642..0d96a6a 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2854,7 +2854,7 @@ reindex_index(Oid indexId, bool skip_constraint_checks)
 		}
 
 		/* We'll build a new physical relation for the index */
-		RelationSetNewRelfilenode(iRel, InvalidTransactionId);
+		RelationSetNewRelfilenode(iRel, InvalidTransactionId, InvalidTransactionId);
 
 		/* Initialize the index and rebuild */
 		/* Note: we do not need to re-establish pkey setting */
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index b40e57b..0578241 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -82,6 +82,8 @@ static int	elevel = -1;
 
 static MemoryContext anl_context = NULL;
 
+static TransactionId OldestXmin;
+
 static BufferAccessStrategy vac_strategy;
 
 
@@ -538,7 +540,8 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
 							totalrows,
 							visibilitymap_count(onerel),
 							hasindex,
-							InvalidTransactionId);
+							InvalidTransactionId,
+							OldestXmin);
 
 	/*
 	 * Same for indexes. Vacuum always scans all indexes, so if we're part of
@@ -558,6 +561,7 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
 								totalindexrows,
 								0,
 								false,
+								InvalidTransactionId,
 								InvalidTransactionId);
 		}
 	}
@@ -1025,7 +1029,6 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 	double		deadrows = 0;	/* # dead rows seen */
 	double		rowstoskip = -1;	/* -1 means not set yet */
 	BlockNumber totalblocks;
-	TransactionId OldestXmin;
 	BlockSamplerData bs;
 	double		rstate;
 
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 1f95abc..ab4aec2 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -287,7 +287,7 @@ ResetSequence(Oid seq_relid)
 	 * Create a new storage file for the sequence.	We want to keep the
 	 * sequence's relfrozenxid at 0, since it won't contain any unfrozen XIDs.
 	 */
-	RelationSetNewRelfilenode(seq_rel, InvalidTransactionId);
+	RelationSetNewRelfilenode(seq_rel, InvalidTransactionId, InvalidTransactionId);
 
 	/*
 	 * Insert the modified tuple into the new storage file.
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cd4490a..aa9d2e9 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -19,6 +19,7 @@
 #include "access/reloptions.h"
 #include "access/relscan.h"
 #include "access/sysattr.h"
+#include "access/transam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
@@ -1121,7 +1122,7 @@ ExecuteTruncate(TruncateStmt *stmt)
 			 * as the relfilenode value. The old storage file is scheduled for
 			 * deletion at commit.
 			 */
-			RelationSetNewRelfilenode(rel, RecentXmin);
+			RelationSetNewRelfilenode(rel, RecentXmin, GetCurrentTransactionId());
 
 			heap_relid = RelationGetRelid(rel);
 			toast_relid = rel->rd_rel->reltoastrelid;
@@ -1132,7 +1133,12 @@ ExecuteTruncate(TruncateStmt *stmt)
 			if (OidIsValid(toast_relid))
 			{
 				rel = relation_open(toast_relid, AccessExclusiveLock);
-				RelationSetNewRelfilenode(rel, RecentXmin);
+				RelationSetNewRelfilenode(rel, RecentXmin, InvalidTransactionId);
+
+				/*
+				 * We don't need a cmin here because there can't be any open
+				 * cursors in the same session as the TRUNCATE command.
+				 */
 				heap_close(rel, NoLock);
 			}
 
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 353af50..7609e59 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -573,7 +573,8 @@ void
 vac_update_relstats(Relation relation,
 					BlockNumber num_pages, double num_tuples,
 					BlockNumber num_all_visible_pages,
-					bool hasindex, TransactionId frozenxid)
+					bool hasindex, TransactionId frozenxid,
+					TransactionId oldestxmin)
 {
 	Oid			relid = RelationGetRelid(relation);
 	Relation	rd;
@@ -647,6 +648,17 @@ vac_update_relstats(Relation relation,
 		dirty = true;
 	}
 
+	/*
+	 * Reset relvalidxmin if its old enough
+	 */
+	if (TransactionIdIsValid(oldestxmin) &&
+		TransactionIdIsNormal(pgcform->relvalidxmin) &&
+		TransactionIdPrecedes(pgcform->relvalidxmin, oldestxmin))
+	{
+		pgcform->relvalidxmin = InvalidTransactionId;
+		dirty = true;
+	}
+
 	/* If anything changed, write out the tuple. */
 	if (dirty)
 		heap_inplace_update(rd, ctup);
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 2fc749e..46d6ab8 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -255,7 +255,8 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
 						new_rel_tuples,
 						new_rel_allvisible,
 						vacrelstats->hasindex,
-						new_frozen_xid);
+						new_frozen_xid,
+						OldestXmin);
 
 	/* report results to the stats collector, too */
 	pgstat_report_vacuum(RelationGetRelid(onerel),
@@ -1185,6 +1186,7 @@ lazy_cleanup_index(Relation indrel,
 							stats->num_index_tuples,
 							0,
 							false,
+							InvalidTransactionId,
 							InvalidTransactionId);
 
 	ereport(elevel,
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index a59950e..17303e8 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -2605,7 +2605,8 @@ RelationBuildLocalRelation(const char *relname,
  * the XIDs that will be put into the new relation contents.
  */
 void
-RelationSetNewRelfilenode(Relation relation, TransactionId freezeXid)
+RelationSetNewRelfilenode(Relation relation, TransactionId freezeXid,
+						  TransactionId validxmin)
 {
 	Oid			newrelfilenode;
 	RelFileNodeBackend newrnode;
@@ -2674,6 +2675,10 @@ RelationSetNewRelfilenode(Relation relation, TransactionId freezeXid)
 	}
 	classform->relfrozenxid = freezeXid;
 
+	if (validxmin != InvalidTransactionId &&
+		TransactionIdPrecedes(classform->relvalidxmin, validxmin))
+		classform->relvalidxmin = validxmin;
+
 	simple_heap_update(pg_class, &tuple->t_self, tuple);
 	CatalogUpdateIndexes(pg_class, tuple);
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 486bdcd..1561889 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1430,6 +1430,19 @@ static struct config_bool ConfigureNamesBool[] =
 	},
 
 	{
+		{"strict_mvcc", PGC_POSTMASTER, COMPAT_OPTIONS_PREVIOUS,
+			gettext_noop("Enables backward compatibility mode of strict MVCC "
+						 "for TRUNCATE and CREATE TABLE."),
+			gettext_noop("When enabled viewing a truncated or newly created table "
+						 "will throw a serialization error to prevent MVCC "
+						 "discrepancies that were possible priot to 9.2.")
+		},
+		&StrictMVCC,
+		true,
+		NULL, NULL, NULL
+	},
+
+	{
 		{"quote_all_identifiers", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 			gettext_noop("When generating SQL fragments, quote all identifiers."),
 			NULL,
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 96da086..f56e374 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -548,6 +548,7 @@
 #quote_all_identifiers = off
 #sql_inheritance = on
 #standard_conforming_strings = on
+#strict_mvcc = on
 #synchronize_seqscans = on
 
 # - Other Platforms and Clients -
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 0335347..223f157 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201203021
+#define CATALOG_VERSION_NO	201203031
 
 #endif
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 1567206..d6ee70c 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -67,6 +67,7 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 	bool		relhastriggers; /* has (or has had) any TRIGGERs */
 	bool		relhassubclass; /* has (or has had) derived classes */
 	TransactionId relfrozenxid; /* all Xids < this are frozen in this rel */
+	TransactionId relvalidxmin;	/* data is only valid for snapshots > this Xid */
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	/* NOTE: These fields are not present in a relcache entry's rd_rel field. */
@@ -77,7 +78,7 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 
 /* Size of fixed part of pg_class tuples, not counting var-length fields */
 #define CLASS_TUPLE_SIZE \
-	 (offsetof(FormData_pg_class,relfrozenxid) + sizeof(TransactionId))
+	 (offsetof(FormData_pg_class,relvalidxmin) + sizeof(TransactionId))
 
 /* ----------------
  *		Form_pg_class corresponds to a pointer to a tuple with
@@ -91,7 +92,7 @@ typedef FormData_pg_class *Form_pg_class;
  * ----------------
  */
 
-#define Natts_pg_class					27
+#define Natts_pg_class					28
 #define Anum_pg_class_relname			1
 #define Anum_pg_class_relnamespace		2
 #define Anum_pg_class_reltype			3
@@ -117,8 +118,9 @@ typedef FormData_pg_class *Form_pg_class;
 #define Anum_pg_class_relhastriggers	23
 #define Anum_pg_class_relhassubclass	24
 #define Anum_pg_class_relfrozenxid		25
-#define Anum_pg_class_relacl			26
-#define Anum_pg_class_reloptions		27
+#define Anum_pg_class_relvalidxmin		26
+#define Anum_pg_class_relacl			27
+#define Anum_pg_class_reloptions		28
 
 /* ----------------
  *		initial contents of pg_class
@@ -130,13 +132,13 @@ typedef FormData_pg_class *Form_pg_class;
  */
 
 /* Note: "3" in the relfrozenxid column stands for FirstNormalTransactionId */
-DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 0 f f p r 30 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 0 f f p r 30 0 t f f f f 3 0 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 0 f f p r 21 0 f f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 0 f f p r 21 0 f f f f f 3 0 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 0 f f p r 27 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 0 f f p r 27 0 t f f f f 3 0 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 0 f f p r 27 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 0 f f p r 28 0 t f f f f 3 0 _null_ _null_ ));
 DESCR("");
 
 
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index 4526648..fa79231 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -151,7 +151,8 @@ extern void vac_update_relstats(Relation relation,
 					double num_tuples,
 					BlockNumber num_all_visible_pages,
 					bool hasindex,
-					TransactionId frozenxid);
+					TransactionId frozenxid,
+					TransactionId oldestxmin);
 extern void vacuum_set_xid_limits(int freeze_min_age, int freeze_table_age,
 					  bool sharedRel,
 					  TransactionId *oldestXmin,
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 610cb59..9d2be31 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -342,6 +342,8 @@ extern ProcessingMode Mode;
 
 #define GetProcessingMode() Mode
 
+/* in access/heap/heapam.c */
+extern bool	StrictMVCC;
 
 /*****************************************************************************
  *	  pinit.h --															 *
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index 2f39486..60c2eb6 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -76,7 +76,8 @@ extern Relation RelationBuildLocalRelation(const char *relname,
  * Routine to manage assignment of new relfilenode to a relation
  */
 extern void RelationSetNewRelfilenode(Relation relation,
-						  TransactionId freezeXid);
+						  TransactionId freezeXid,
+						  TransactionId validxmin);
 
 /*
  * Routines for flushing/rebuilding relcache entries in various scenarios
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 669c0f2..bba722a 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -14,3 +14,4 @@ test: fk-contention
 test: fk-deadlock
 test: fk-deadlock2
 test: eval-plan-qual
+test: truncate
diff --git a/src/test/isolation/expected/truncate.out b/src/test/isolation/expected/truncate.out
new file mode 100644
index ...2b9f161
*** a/src/test/isolation/expected/truncate.out
--- b/src/test/isolation/expected/truncate.out
***************
*** 0 ****
--- 1,63 ----
+ Parsed test spec with 2 sessions
+ 
+ starting permutation: begin select roll trunc
+ step begin: 
+   BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+   -- Force snapshot open
+   SELECT 1 AS foo FROM txid_current();
+ 
+ foo            
+ 
+ 1              
+ step select: SELECT * FROM foo;
+ i              
+ 
+ 1              
+ step roll: ROLLBACK;
+ step trunc: TRUNCATE TABLE foo;
+ 
+ starting permutation: begin select trunc roll
+ step begin: 
+   BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+   -- Force snapshot open
+   SELECT 1 AS foo FROM txid_current();
+ 
+ foo            
+ 
+ 1              
+ step select: SELECT * FROM foo;
+ i              
+ 
+ 1              
+ step trunc: TRUNCATE TABLE foo; <waiting ...>
+ step roll: ROLLBACK;
+ step trunc: <... completed>
+ 
+ starting permutation: begin trunc select roll
+ step begin: 
+   BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+   -- Force snapshot open
+   SELECT 1 AS foo FROM txid_current();
+ 
+ foo            
+ 
+ 1              
+ step trunc: TRUNCATE TABLE foo;
+ step select: SELECT * FROM foo;
+ ERROR:  canceling statement due to conflict with TRUNCATE TABLE on foo
+ step roll: ROLLBACK;
+ 
+ starting permutation: trunc begin select roll
+ step trunc: TRUNCATE TABLE foo;
+ step begin: 
+   BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+   -- Force snapshot open
+   SELECT 1 AS foo FROM txid_current();
+ 
+ foo            
+ 
+ 1              
+ step select: SELECT * FROM foo;
+ i              
+ 
+ step roll: ROLLBACK;
diff --git a/src/test/isolation/specs/truncate.spec b/src/test/isolation/specs/truncate.spec
new file mode 100644
index ...2c7b707
*** a/src/test/isolation/specs/truncate.spec
--- b/src/test/isolation/specs/truncate.spec
***************
*** 0 ****
--- 1,23 ----
+ setup
+ {
+   CREATE TABLE foo (i int);
+   INSERT INTO foo VALUES (1);
+ }
+ 
+ teardown
+ {
+   DROP TABLE foo;
+ }
+ 
+ session "s1"
+ step "begin"
+ {
+   BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+   -- Force snapshot open
+   SELECT 1 AS foo FROM txid_current();
+ }
+ step "select"	{ SELECT * FROM foo; }
+ step "roll"		{ ROLLBACK; }
+ 
+ session "s2"
+ step "trunc"	{ TRUNCATE TABLE foo; }