Transaction control in procedures

From 522c8f20ddcb3f670b0a5687bdc4c7b18d5eaeae Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 14 Nov 2017 18:00:26 -0500
Subject: [PATCH v2] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL statement so that transaction control commands can only
be issued in top-level procedure calls, not function calls or other
procedure calls.
---
 src/backend/commands/functioncmds.c               | 29 ++++++-
 src/backend/executor/spi.c                        | 93 +++++++++++++++++-----
 src/backend/tcop/utility.c                        |  2 +-
 src/backend/utils/mmgr/portalmem.c                | 39 ++++-----
 src/include/commands/defrem.h                     | 12 ++-
 src/include/executor/spi.h                        |  5 ++
 src/include/executor/spi_priv.h                   |  4 +
 src/include/nodes/nodes.h                         |  3 +-
 src/pl/plperl/GNUmakefile                         |  2 +-
 src/pl/plperl/SPI.xs                              | 12 +++
 src/pl/plperl/expected/plperl_transaction.out     | 85 ++++++++++++++++++++
 src/pl/plperl/plperl.c                            |  6 ++
 src/pl/plperl/sql/plperl_transaction.sql          | 76 ++++++++++++++++++
 src/pl/plpgsql/src/pl_exec.c                      | 48 +++++++++++-
 src/pl/plpgsql/src/pl_funcs.c                     | 44 +++++++++++
 src/pl/plpgsql/src/pl_gram.y                      | 34 ++++++++
 src/pl/plpgsql/src/pl_handler.c                   |  8 ++
 src/pl/plpgsql/src/pl_scanner.c                   |  2 +
 src/pl/plpgsql/src/plpgsql.h                      | 22 +++++-
 src/pl/plpython/Makefile                          |  1 +
 src/pl/plpython/expected/plpython_test.out        |  9 ++-
 src/pl/plpython/expected/plpython_transaction.out | 83 ++++++++++++++++++++
 src/pl/plpython/plpy_main.c                       |  7 +-
 src/pl/plpython/plpy_plpymodule.c                 | 38 +++++++++
 src/pl/plpython/sql/plpython_transaction.sql      | 69 ++++++++++++++++
 src/pl/tcl/Makefile                               |  2 +-
 src/pl/tcl/expected/pltcl_transaction.out         | 63 +++++++++++++++
 src/pl/tcl/pltcl.c                                | 45 +++++++++++
 src/pl/tcl/sql/pltcl_transaction.sql              | 60 ++++++++++++++
 src/test/regress/expected/plpgsql.out             | 96 +++++++++++++++++++++++
 src/test/regress/sql/plpgsql.sql                  | 82 +++++++++++++++++++
 31 files changed, 1025 insertions(+), 56 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 1f3156d870..263f3a69c4 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2207,9 +2208,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2220,6 +2240,7 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2255,8 +2276,12 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	MemoryContextSwitchTo(PortalContext);
+
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 2da1cac3e2..7d47a90638 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -92,7 +92,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,6 +124,7 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = true;	/* until told otherwise */
 
 	/*
 	 * Create memory contexts for this procedure
@@ -133,10 +134,10 @@ SPI_connect(void)
 	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
 	 * because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -145,6 +146,17 @@ SPI_connect(void)
 	return SPI_OK_CONNECT;
 }
 
+int
+SPI_set_nonatomic(void)
+{
+	if (_SPI_current == NULL)
+		return SPI_ERROR_UNCONNECTED;
+
+	_SPI_current->atomic = false;
+
+	return SPI_OK_CONNECT;
+}
+
 int
 SPI_finish(void)
 {
@@ -158,8 +170,6 @@ SPI_finish(void)
 	MemoryContextSwitchTo(_SPI_current->savedcxt);
 
 	/* Release memory used in procedure call (including tuptables) */
-	MemoryContextDelete(_SPI_current->execCxt);
-	_SPI_current->execCxt = NULL;
 	MemoryContextDelete(_SPI_current->procCxt);
 	_SPI_current->procCxt = NULL;
 
@@ -181,12 +191,68 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+int
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+	return 0;
+}
+
+
+int
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
+int
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,21 +290,10 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
-		found = true;
+		if (connection->internal_xact)
+			break;
 
-		/*
-		 * Release procedure memory explicitly (see note in SPI_connect)
-		 */
-		if (connection->execCxt)
-		{
-			MemoryContextDelete(connection->execCxt);
-			connection->execCxt = NULL;
-		}
-		if (connection->procCxt)
-		{
-			MemoryContextDelete(connection->procCxt);
-			connection->procCxt = NULL;
-		}
+		found = true;
 
 		/*
 		 * Pop the stack entry and reset global variables.  Unlike
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4da1f8f643..1e8de07e11 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -658,7 +658,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree), context != PROCESS_UTILITY_TOPLEVEL);
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index d03b779407..1b217c312a 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -736,11 +736,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -754,17 +751,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -799,14 +785,6 @@ AtAbort_Portals(void)
 		 * PortalDrop.
 		 */
 		portal->resowner = NULL;
-
-		/*
-		 * Although we can't delete the portal data structure proper, we can
-		 * release any memory in subsidiary contexts, such as executor state.
-		 * The cleanup hook was the last thing that might have needed data
-		 * there.
-		 */
-		MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
 	}
 }
 
@@ -826,6 +804,19 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 *
+		 * Note however that any resource owner attached to such a portal is
+		 * still going to go away, so don't leave a dangling pointer.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+		{
+			portal->resowner = NULL;
+			continue;
+		}
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 52cbf61ccb..8ebe3c48aa 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -59,7 +59,7 @@ extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
 extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
@@ -74,6 +74,16 @@ extern void interpret_function_parameter_list(ParseState *pstate,
 								  Oid *variadicArgType,
 								  Oid *requiredResultType);
 
+/*
+ * Procedure call context information
+ */
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
+
 /* commands/operatorcmds.c */
 extern ObjectAddress DefineOperator(List *names, List *parameters);
 extern void RemoveOperatorById(Oid operOid);
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index acade7e92e..e38158c54e 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -78,6 +78,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_set_nonatomic(void);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +157,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern int	SPI_start_transaction(void);
+extern int	SPI_commit(void);
+extern int	SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 8fae755418..9dc8af22e4 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 43ee88bd39..82dbf4e177 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -499,7 +499,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in commands/defrem.h */
 } NodeTag;
 
 /*
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..dc9ddedc8f 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,17 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		SPI_commit();
+		SPI_start_transaction();
+
+void
+spi_spi_rollback()
+	CODE:
+		SPI_rollback();
+		SPI_start_transaction();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..38e9651d3e
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,85 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+-- FIXME
+--SELECT transaction_test3();
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 9f5313235f..f3133e816b 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -23,6 +23,7 @@
 #include "catalog/pg_proc.h"
 #include "catalog/pg_proc_fn.h"
 #include "catalog/pg_type.h"
+#include "commands/defrem.h"
 #include "commands/event_trigger.h"
 #include "commands/trigger.h"
 #include "executor/spi.h"
@@ -1931,6 +1932,7 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		if (SPI_connect() != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
+		SPI_set_nonatomic();
 
 		select_perl_context(desc.lanpltrusted);
 
@@ -2409,6 +2411,10 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 	current_call_data->prodesc = prodesc;
 	increment_prodesc_refcount(prodesc);
 
+	if (prodesc->result_oid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	/* Set a callback for error reporting */
 	pl_error_context.callback = plperl_exec_callback;
 	pl_error_context.previous = error_context_stack;
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..864a3e396c
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,76 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+-- FIXME
+--SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 882b16e2b1..2943618d62 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -215,6 +215,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1652,6 +1656,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4356,6 +4368,39 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6858,7 +6903,8 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
 		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		//Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 23f54e1c21..a3a45916d1 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1243,6 +1273,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 94f1f58593..e661750176 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -199,6 +199,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -261,6 +262,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -326,6 +328,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -898,6 +901,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2174,6 +2181,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2410,6 +2442,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2461,6 +2494,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 1ebb7a7b5e..93a7ff2df3 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -18,6 +18,7 @@
 #include "access/htup_details.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
+#include "commands/defrem.h"
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "utils/builtins.h"
@@ -255,7 +256,12 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
+			if (func->fn_rettype == InvalidOid &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+				SPI_set_nonatomic();
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -304,6 +310,8 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
+	SPI_set_nonatomic();
+
 	/* Compile the anonymous code block */
 	func = plpgsql_compile_inline(codeblock->source_text);
 
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index 553be8c93c..a172031db2 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 2b19948562..8494a4374d 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..f0a10cc05f 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -43,11 +43,12 @@ contents.sort()
 return contents
 $$ LANGUAGE plpythonu;
 select module_contents();
- module_contents 
------------------
+  module_contents  
+-------------------
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,12 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
+ start_transaction
  subtransaction
  warning
-(18 rows)
+(21 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..c664b5d1d2
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,83 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 7df50c09c8..ae83fcf5d1 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -9,6 +9,7 @@
 #include "access/htup_details.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
+#include "commands/defrem.h"
 #include "commands/trigger.h"
 #include "executor/spi.h"
 #include "miscadmin.h"
@@ -262,6 +263,9 @@ plpython_call_handler(PG_FUNCTION_ARGS)
 		else
 		{
 			proc = PLy_procedure_get(funcoid, InvalidOid, false);
+			if (proc->is_procedure &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+					SPI_set_nonatomic();
 			exec_ctx->curr_proc = proc;
 			retval = PLy_exec_function(fcinfo, proc);
 		}
@@ -305,6 +309,7 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
 	if (SPI_connect() != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
+	SPI_set_nonatomic();
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
 	MemSet(&flinfo, 0, sizeof(flinfo));
@@ -424,7 +429,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 759ad44932..a95e66bfee 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -41,6 +43,9 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_start_transaction(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +100,13 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"start_transaction", PLy_start_transaction, METH_NOARGS, NULL},
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +589,29 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_start_transaction(PyObject *self, PyObject *args)
+{
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..ac98a81e1b
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,69 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..6ce900027c
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,63 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index e0792d93e1..816882e92c 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -18,6 +18,7 @@
 #include "catalog/objectaccess.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
+#include "commands/defrem.h"
 #include "commands/event_trigger.h"
 #include "commands/trigger.h"
 #include "executor/spi.h"
@@ -312,6 +313,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +529,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -812,6 +821,10 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid, InvalidOid,
 									 false, pltrusted);
 
+	if (prodesc->result_typid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	call_state->prodesc = prodesc;
 	prodesc->fn_refcount++;
 
@@ -2935,6 +2948,38 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..14aed5844a
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,60 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index d6e5bc3353..040f667f8e 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -6077,7 +6077,103 @@ SELECT * FROM proc_test1;
  55
 (1 row)
 
+TRUNCATE proc_test1;
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL test_proc_transaction1();
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+TRUNCATE proc_test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+TRUNCATE proc_test1;
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT test_proc_transaction2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction2() line 6 at COMMIT
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+SELECT test_proc_transaction3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction1() line 6 at COMMIT
+SQL statement "CALL test_proc_transaction1()"
+PL/pgSQL function test_proc_transaction3() line 3 at SQL statement
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 DROP TABLE proc_test1;
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index 1c355132b7..a0e4821e0c 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -4864,8 +4864,90 @@ CREATE PROCEDURE test_proc3(x int)
 SELECT * FROM proc_test1;
 
 
+TRUNCATE proc_test1;
+
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL test_proc_transaction1();
+
+SELECT * FROM proc_test1;
+
+
+TRUNCATE proc_test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM proc_test1;
+
+
+TRUNCATE proc_test1;
+
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT test_proc_transaction2();
+
+SELECT * FROM proc_test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+
+SELECT test_proc_transaction3();
+
+SELECT * FROM proc_test1;
+
+
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 
 DROP TABLE proc_test1;
-- 
2.15.0

From 1a5e5fde2c0da663cc010b3e19418d0b2141304b Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Fri, 1 Dec 2017 14:40:29 -0500
Subject: [PATCH v3] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.
---
 doc/src/sgml/plperl.sgml                          |  49 +++++
 doc/src/sgml/plpgsql.sgml                         |  86 +++++----
 doc/src/sgml/plpython.sgml                        |  34 ++++
 doc/src/sgml/pltcl.sgml                           |  37 ++++
 doc/src/sgml/spi.sgml                             | 219 ++++++++++++++++++++++
 src/backend/commands/functioncmds.c               |  30 ++-
 src/backend/executor/spi.c                        |  92 +++++++--
 src/backend/tcop/utility.c                        |   4 +-
 src/backend/utils/mmgr/portalmem.c                |  39 ++--
 src/include/commands/defrem.h                     |   4 +-
 src/include/executor/spi.h                        |   5 +
 src/include/executor/spi_priv.h                   |   4 +
 src/include/nodes/nodes.h                         |   3 +-
 src/include/nodes/parsenodes.h                    |   7 +
 src/pl/plperl/GNUmakefile                         |   2 +-
 src/pl/plperl/SPI.xs                              |  12 ++
 src/pl/plperl/expected/plperl_transaction.out     |  94 ++++++++++
 src/pl/plperl/plperl.c                            |   6 +
 src/pl/plperl/sql/plperl_transaction.sql          |  88 +++++++++
 src/pl/plpgsql/src/pl_exec.c                      |  48 ++++-
 src/pl/plpgsql/src/pl_funcs.c                     |  44 +++++
 src/pl/plpgsql/src/pl_gram.y                      |  34 ++++
 src/pl/plpgsql/src/pl_handler.c                   |   8 +
 src/pl/plpgsql/src/pl_scanner.c                   |   2 +
 src/pl/plpgsql/src/plpgsql.h                      |  22 ++-
 src/pl/plpython/Makefile                          |   1 +
 src/pl/plpython/expected/plpython_test.out        |   4 +-
 src/pl/plpython/expected/plpython_transaction.out |  96 ++++++++++
 src/pl/plpython/plpy_main.c                       |   7 +-
 src/pl/plpython/plpy_plpymodule.c                 |  28 +++
 src/pl/plpython/sql/plpython_transaction.sql      |  80 ++++++++
 src/pl/tcl/Makefile                               |   2 +-
 src/pl/tcl/expected/pltcl_transaction.out         |  63 +++++++
 src/pl/tcl/pltcl.c                                |  44 +++++
 src/pl/tcl/sql/pltcl_transaction.sql              |  60 ++++++
 src/test/regress/expected/plpgsql.out             | 110 +++++++++++
 src/test/regress/sql/plpgsql.sql                  |  95 ++++++++++
 37 files changed, 1461 insertions(+), 102 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 100162dead..82ddf26606 100644
--- a/doc/src/sgml/plperl.sgml
+++ b/doc/src/sgml/plperl.sgml
@@ -661,6 +661,55 @@ <title>Database Access from PL/Perl</title>
     </para>
     </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term>
+      <literal><function>spi_commit()</function></literal>
+      <indexterm>
+       <primary>spi_commit</primary>
+       <secondary>in PL/Perl</secondary>
+     </indexterm>
+     </term>
+     <term>
+      <literal><function>spi_rollback()</function></literal>
+      <indexterm>
+       <primary>spi_rollback</primary>
+       <secondary>in PL/Perl</secondary>
+      </indexterm>
+     </term>
+     <listitem>
+      <para>
+       Commit or roll back the current transaction.  This can only be called
+       in a procedure or anonymous code block called from the top level.
+       (Note that it is not possible to run the SQL
+       commands <command>COMMIT</command> or <command>ROLLBACK</command>
+       via <function>spi_exec_query</function> or similar.  It has to be done
+       using these functions.)  After a transaction is ended, a new
+       transaction is automatically started, so there is no separate function
+       for that.
+      </para>
+
+      <para>
+       Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
  </sect2>
 
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 7d23ed437e..4e0334c530 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3449,6 +3449,43 @@ <title>Looping Through a Cursor's Result</title>
 
   </sect1>
 
+  <sect1 id="plpgsql-transactions">
+   <title>Transaction Management</title>
+
+   <para>
+    In procedures invoked by the <command>CALL</command> command from the top
+    level as well as in anonymous code blocks called from the top level, it is
+    possible to end transactions using the commands <command>COMMIT</command>
+    and <command>ROLLBACK</command>.  A new transaction is started
+    automatically after a transaction is ended using these commands, so there
+    is no separate <command>START TRANSACTION</command> command.  (And of
+    course, <command>BEGIN</command> and <command>END</command> have different
+    meanings in PL/pgSQL.)
+   </para>
+
+   <para>
+    Here is a simple example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+</programlisting>
+   </para>
+  </sect1>
+
   <sect1 id="plpgsql-errors-and-messages">
    <title>Errors and Messages</title>
 
@@ -5432,14 +5469,13 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 <programlisting>
 CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS
     a_running_job_count INTEGER;
-    PRAGMA AUTONOMOUS_TRANSACTION; -- <co id="co.plpgsql-porting-pragma"/>
 BEGIN
-    LOCK TABLE cs_jobs IN EXCLUSIVE MODE; -- <co id="co.plpgsql-porting-locktable"/>
+    LOCK TABLE cs_jobs IN EXCLUSIVE MODE;
 
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
-        COMMIT; -- free lock <co id="co.plpgsql-porting-commit"/>
+        COMMIT; -- free lock
         raise_application_error(-20000,
                  'Unable to create a new job: a job is currently running.');
     END IF;
@@ -5459,45 +5495,11 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 </programlisting>
    </para>
 
-   <para>
-    Procedures like this can easily be converted into <productname>PostgreSQL</productname>
-    functions returning <type>void</type>. This procedure in
-    particular is interesting because it can teach us some things:
-
-    <calloutlist>
-     <callout arearefs="co.plpgsql-porting-pragma">
-      <para>
-       There is no <literal>PRAGMA</literal> statement in <productname>PostgreSQL</productname>.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-locktable">
-      <para>
-       If you do a <command>LOCK TABLE</command> in <application>PL/pgSQL</application>,
-       the lock will not be released until the calling transaction is
-       finished.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-commit">
-      <para>
-       You cannot issue <command>COMMIT</command> in a
-       <application>PL/pgSQL</application> function.  The function is
-       running within some outer transaction and so <command>COMMIT</command>
-       would imply terminating the function's execution.  However, in
-       this particular case it is not necessary anyway, because the lock
-       obtained by the <command>LOCK TABLE</command> will be released when
-       we raise an error.
-      </para>
-     </callout>
-    </calloutlist>
-   </para>
-
    <para>
     This is how we could port this procedure to <application>PL/pgSQL</application>:
 
 <programlisting>
-CREATE OR REPLACE FUNCTION cs_create_job(v_job_id integer) RETURNS void AS $$
+CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id integer) AS $$
 DECLARE
     a_running_job_count integer;
 BEGIN
@@ -5506,6 +5508,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
+        COMMIT; -- free lock
         RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; -- <co id="co.plpgsql-porting-raise"/>
     END IF;
 
@@ -5518,6 +5521,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
         WHEN unique_violation THEN -- <co id="co.plpgsql-porting-exception"/>
             -- don't worry if it already exists
     END;
+    COMMIT;
 END;
 $$ LANGUAGE plpgsql;
 </programlisting>
@@ -5541,12 +5545,6 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
       </para>
      </callout>
     </calloutlist>
-
-    The main functional difference between this procedure and the
-    Oracle equivalent is that the exclusive lock on the <literal>cs_jobs</literal>
-    table will be held until the calling transaction completes.  Also, if
-    the caller later aborts (for example due to an error), the effects of
-    this procedure will be rolled back.
    </para>
    </example>
   </sect2>
diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 0dbeee1fa2..3f2e141085 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -1370,6 +1370,40 @@ <title>Older Python Versions</title>
   </sect2>
  </sect1>
 
+ <sect1 id="plpython-transactions">
+  <title>Transaction Management</title>
+
+  <para>
+   In a procedure called from the top level or an anonymous code block called
+   from the top level it is possible to control transactions.  To commit the
+   current transaction, call <literal>plpy.commit()</literal>.  To roll back
+   the current transaction, call <literal>plpy.rollback()</literal>.  (Note
+   that it is not possible to run the SQL commands <command>COMMIT</command>
+   or <command>ROLLBACK</command> via <function>plpy.execute</function> or
+   similar.  It has to be done using these functions.)  After a transaction is
+   ended, a new transaction is automatically started, so there is no separate
+   function for that.
+  </para>
+
+  <para>
+   Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+</programlisting>
+  </para>
+ </sect1>
+
  <sect1 id="plpython-util">
   <title>Utility Functions</title>
   <para>
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml
index 8018783b0a..de12b20a73 100644
--- a/doc/src/sgml/pltcl.sgml
+++ b/doc/src/sgml/pltcl.sgml
@@ -1002,6 +1002,43 @@ <title>Explicit Subtransactions in PL/Tcl</title>
     </para>
    </sect1>
 
+   <sect1 id="pltcl-transactions">
+    <title>Transaction Management</title>
+
+    <para>
+     In a procedure called from the top level or an anonymous code block
+     called from the top level it is possible to control transactions.  To
+     commit the current transaction, call the <literal>commit</literal>
+     command.  To roll back the current transaction, call
+     the <literal>rollback</literal> command.  (Note that it is not possible
+     to run the SQL commands <command>COMMIT</command>
+     or <command>ROLLBACK</command> via <function>spi_exec</function> or
+     similar.  It has to be done using these functions.)  After a transaction
+     is ended, a new transaction is automatically started, so there is no
+     separate command for that.
+    </para>
+
+    <para>
+     Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i &lt; 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+    </para>
+   </sect1>
+
    <sect1 id="pltcl-config">
     <title>PL/Tcl Configuration</title>
 
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 350f0863e9..6df8f8368b 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -4325,6 +4325,225 @@ <title>Return Value</title>
 
  </sect1>
 
+ <sect1 id="spi-transaction">
+  <title>Transaction Management</title>
+
+  <para>
+   It is not possible to run transaction control commands such
+   as <command>COMMIT</command> and <command>ROLLBACK</command> through SPI
+   functions such as <function>SPI_execute</function>.  There are, however,
+   separate interface functions that allow transaction control through SPI.
+  </para>
+
+  <para>
+   It is not generally safe and sensible to start and end transactions in
+   arbitrary user-defined SQL-callable functions without taking into account
+   the context in which they are called.  For example, a transaction boundary
+   in the middle of a function that is part of a complex SQL expression that
+   is part of some SQL command will probably result in obscure internal errors
+   or crashes.  The interface functions presented here are primarily intended
+   to be used by procedural language implementations to support transaction
+   management in procedures that are invoked by the <command>CALL</command>
+   command, taking the context of the <command>CALL</command> invocation into
+   account.  SPI procedures implemented in C can implement the same logic, but
+   the details of that are beyond the scope of this documentation.
+  </para>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-commit">
+ <indexterm><primary>SPI_commit</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_commit</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_commit</refname>
+  <refpurpose>commit the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_commit(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_commit</function> commits the current transaction.  It is
+   approximately equivalent to running the SQL
+   command <command>COMMIT</command>.  After a transaction is committed, a new
+   transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-rollback">
+ <indexterm><primary>SPI_rollback</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_rollback</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_rollback</refname>
+  <refpurpose>abort the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_rollback(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_rollback</function> rolls back the current transaction.  It
+   is approximately equivalent to running the SQL
+   command <command>ROLLBACK</command>.  After a transaction is rolled back, a
+   new transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-set-nonatomic">
+ <indexterm><primary>SPI_set_nonatomic</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_set_nonatomic</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_set_nonatomic</refname>
+  <refpurpose>makes current SPI connection nonatomic</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_set_nonatomic(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_set_nonatomic</function> sets the current SPI connection to
+   be <firstterm>nonatomic</firstterm>, which means that transaction control
+   calls <function>SPI_commit</function>, <function>SPI_rollback</function>,
+   and <function>SPI_start_transaction</function> are allowed.  Otherwise,
+   calling these functions will result in an immediate
+   error.  <function>SPI_set_nonatomic</function> has to be called
+   after <function>SPI_connect</function> and its effects are canceled by the
+   corresponding <function>SPI_finish</function>, but it can be called at any
+   point in between.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-start-transaction">
+ <indexterm><primary>SPI_start_transaction</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_start_transaction</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_start_transaction</refname>
+  <refpurpose>start a new transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_start_transaction(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_start_transaction</function> starts a new transaction.  It
+   can only be called after <function>SPI_commit</function>
+   or <function>SPI_rollback</function>, as there is no transaction active at
+   that point.  Normally, when an SPI procedure is called, there is already a
+   transaction active, so attempting to start another one before closing out
+   the current one will result in an error.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+ </sect1>
+
  <sect1 id="spi-visibility">
   <title>Visibility of Data Changes</title>
 
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 2a9c90133d..81b34522c0 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2138,7 +2139,7 @@ IsThereFunctionInNamespace(const char *proname, int pronargs,
  *		Execute inline procedural-language code
  */
 void
-ExecuteDoStmt(DoStmt *stmt)
+ExecuteDoStmt(DoStmt *stmt, bool atomic)
 {
 	InlineCodeBlock *codeblock = makeNode(InlineCodeBlock);
 	ListCell   *arg;
@@ -2200,6 +2201,7 @@ ExecuteDoStmt(DoStmt *stmt)
 	codeblock->langOid = HeapTupleGetOid(languageTuple);
 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
 	codeblock->langIsTrusted = languageStruct->lanpltrusted;
+	codeblock->atomic = atomic;
 
 	if (languageStruct->lanpltrusted)
 	{
@@ -2236,9 +2238,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2249,6 +2270,7 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2284,8 +2306,10 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 2da1cac3e2..14a59e722f 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -92,7 +92,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,6 +124,7 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = true;	/* until told otherwise */
 
 	/*
 	 * Create memory contexts for this procedure
@@ -133,10 +134,10 @@ SPI_connect(void)
 	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
 	 * because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -145,6 +146,17 @@ SPI_connect(void)
 	return SPI_OK_CONNECT;
 }
 
+int
+SPI_set_nonatomic(void)
+{
+	if (_SPI_current == NULL)
+		return SPI_ERROR_UNCONNECTED;
+
+	_SPI_current->atomic = false;
+
+	return SPI_OK_CONNECT;
+}
+
 int
 SPI_finish(void)
 {
@@ -158,8 +170,6 @@ SPI_finish(void)
 	MemoryContextSwitchTo(_SPI_current->savedcxt);
 
 	/* Release memory used in procedure call (including tuptables) */
-	MemoryContextDelete(_SPI_current->execCxt);
-	_SPI_current->execCxt = NULL;
 	MemoryContextDelete(_SPI_current->procCxt);
 	_SPI_current->procCxt = NULL;
 
@@ -181,12 +191,67 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+int
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+	return 0;
+}
+
+int
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
+int
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,21 +289,10 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
-		found = true;
+		if (connection->internal_xact)
+			break;
 
-		/*
-		 * Release procedure memory explicitly (see note in SPI_connect)
-		 */
-		if (connection->execCxt)
-		{
-			MemoryContextDelete(connection->execCxt);
-			connection->execCxt = NULL;
-		}
-		if (connection->procCxt)
-		{
-			MemoryContextDelete(connection->procCxt);
-			connection->procCxt = NULL;
-		}
+		found = true;
 
 		/*
 		 * Pop the stack entry and reset global variables.  Unlike
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4da1f8f643..b20861066b 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -529,7 +529,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_DoStmt:
-			ExecuteDoStmt((DoStmt *) parsetree);
+			ExecuteDoStmt((DoStmt *) parsetree, context != PROCESS_UTILITY_TOPLEVEL);
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -658,7 +658,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree), context != PROCESS_UTILITY_TOPLEVEL);
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index d03b779407..1b217c312a 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -736,11 +736,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -754,17 +751,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -799,14 +785,6 @@ AtAbort_Portals(void)
 		 * PortalDrop.
 		 */
 		portal->resowner = NULL;
-
-		/*
-		 * Although we can't delete the portal data structure proper, we can
-		 * release any memory in subsidiary contexts, such as executor state.
-		 * The cleanup hook was the last thing that might have needed data
-		 * there.
-		 */
-		MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
 	}
 }
 
@@ -826,6 +804,19 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 *
+		 * Note however that any resource owner attached to such a portal is
+		 * still going to go away, so don't leave a dangling pointer.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+		{
+			portal->resowner = NULL;
+			continue;
+		}
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 52cbf61ccb..b03f5b6a95 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -58,8 +58,8 @@ extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
-extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteDoStmt(DoStmt *stmt, bool atomic);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index acade7e92e..e38158c54e 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -78,6 +78,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_set_nonatomic(void);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +157,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern int	SPI_start_transaction(void);
+extern int	SPI_commit(void);
+extern int	SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 8fae755418..9dc8af22e4 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index c5b5115f5b..6dcd51e958 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -500,7 +500,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in nodes/parsenodes.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2eaa6b2774..cb1afd68f8 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2803,6 +2803,7 @@ typedef struct InlineCodeBlock
 	char	   *source_text;	/* source text of anonymous code block */
 	Oid			langOid;		/* OID of selected language */
 	bool		langIsTrusted;	/* trusted property of the language */
+	bool		atomic;			/* atomic execution context */
 } InlineCodeBlock;
 
 /* ----------------------
@@ -2815,6 +2816,12 @@ typedef struct CallStmt
 	FuncCall   *funccall;
 } CallStmt;
 
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
 /* ----------------------
  *		Alter Object Rename Statement
  * ----------------------
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..dc9ddedc8f 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,17 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		SPI_commit();
+		SPI_start_transaction();
+
+void
+spi_spi_rollback()
+	CODE:
+		SPI_rollback();
+		SPI_start_transaction();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..f7378ce600
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,94 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+-- FIXME
+--SELECT transaction_test3();
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+-- FIXME
+--SELECT transaction_test4();
+DROP TABLE test1;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 9f5313235f..68592033f7 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -1931,6 +1931,8 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		if (SPI_connect() != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
+		if (!codeblock->atomic)
+			SPI_set_nonatomic();
 
 		select_perl_context(desc.lanpltrusted);
 
@@ -2409,6 +2411,10 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 	current_call_data->prodesc = prodesc;
 	increment_prodesc_refcount(prodesc);
 
+	if (prodesc->result_oid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	/* Set a callback for error reporting */
 	pl_error_context.callback = plperl_exec_callback;
 	pl_error_context.previous = error_context_stack;
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..5f15691cfc
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,88 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+-- FIXME
+--SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+
+-- FIXME
+--SELECT transaction_test4();
+
+
+DROP TABLE test1;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index ec480cb0ba..97ee299136 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -215,6 +215,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1652,6 +1656,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4356,6 +4368,39 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6857,8 +6902,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 */
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
-		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 23f54e1c21..a3a45916d1 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1243,6 +1273,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 94f1f58593..e661750176 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -199,6 +199,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -261,6 +262,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -326,6 +328,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -898,6 +901,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2174,6 +2181,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2410,6 +2442,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2461,6 +2494,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 1ebb7a7b5e..6857b0375e 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -255,7 +255,12 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
+			if (func->fn_rettype == InvalidOid &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+				SPI_set_nonatomic();
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -304,6 +309,9 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
+	if (!codeblock->atomic)
+		SPI_set_nonatomic();
+
 	/* Compile the anonymous code block */
 	func = plpgsql_compile_inline(codeblock->source_text);
 
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index 553be8c93c..a172031db2 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 2b19948562..8494a4374d 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..39b994f446 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -48,6 +48,7 @@ select module_contents();
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,11 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
  subtransaction
  warning
-(18 rows)
+(20 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..c5909fdb87
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,96 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+SELECT transaction_test4();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test4", line 2, in <module>
+    plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+PL/Python function "transaction_test4"
+DROP TABLE test1;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 695de30583..254ab37359 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -262,6 +262,9 @@ plpython_call_handler(PG_FUNCTION_ARGS)
 		else
 		{
 			proc = PLy_procedure_get(funcoid, InvalidOid, false);
+			if (proc->is_procedure &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+					SPI_set_nonatomic();
 			exec_ctx->curr_proc = proc;
 			retval = PLy_exec_function(fcinfo, proc);
 		}
@@ -305,6 +308,8 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
 	if (SPI_connect() != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
+	if (!codeblock->atomic)
+		SPI_set_nonatomic();
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
 	MemSet(&flinfo, 0, sizeof(flinfo));
@@ -435,7 +440,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23f99e20ca..b9b9e423a7 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -41,6 +43,8 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +99,12 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +587,21 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..cbcc87f00b
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,80 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+
+SELECT transaction_test4();
+
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..6ce900027c
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,63 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index e0792d93e1..0571755b4f 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -312,6 +312,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +528,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -812,6 +820,10 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid, InvalidOid,
 									 false, pltrusted);
 
+	if (prodesc->result_typid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	call_state->prodesc = prodesc;
 	prodesc->fn_refcount++;
 
@@ -2935,6 +2947,38 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..14aed5844a
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,60 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index d6e5bc3353..3fd5cb6180 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -6077,7 +6077,117 @@ SELECT * FROM proc_test1;
  55
 (1 row)
 
+TRUNCATE proc_test1;
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL test_proc_transaction1();
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+TRUNCATE proc_test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+TRUNCATE proc_test1;
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT test_proc_transaction2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction2() line 6 at COMMIT
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+SELECT test_proc_transaction3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction1() line 6 at COMMIT
+SQL statement "CALL test_proc_transaction1()"
+PL/pgSQL function test_proc_transaction3() line 3 at SQL statement
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION test_proc_transaction4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+SELECT test_proc_transaction4();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+SQL statement "DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$"
+PL/pgSQL function test_proc_transaction4() line 3 at EXECUTE
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 DROP TABLE proc_test1;
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index 1c355132b7..4c1d5da436 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -4864,8 +4864,103 @@ CREATE PROCEDURE test_proc3(x int)
 SELECT * FROM proc_test1;
 
 
+TRUNCATE proc_test1;
+
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL test_proc_transaction1();
+
+SELECT * FROM proc_test1;
+
+
+TRUNCATE proc_test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM proc_test1;
+
+
+TRUNCATE proc_test1;
+
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT test_proc_transaction2();
+
+SELECT * FROM proc_test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+
+SELECT test_proc_transaction3();
+
+SELECT * FROM proc_test1;
+
+
+-- DO block inside function
+CREATE FUNCTION test_proc_transaction4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+
+SELECT test_proc_transaction4();
+
+
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 
 DROP TABLE proc_test1;

base-commit: 87c37e3291cb75273ccdf4645b9472dd805c4493
-- 
2.15.0

From 18aaf292fbb22647e09c38cc21b56ff98643e518 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Wed, 6 Dec 2017 09:29:25 -0500
Subject: [PATCH v4] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.
---
 doc/src/sgml/plperl.sgml                          |  49 +++++
 doc/src/sgml/plpgsql.sgml                         |  91 ++++----
 doc/src/sgml/plpython.sgml                        |  38 ++++
 doc/src/sgml/pltcl.sgml                           |  41 ++++
 doc/src/sgml/ref/call.sgml                        |   7 +
 doc/src/sgml/ref/create_procedure.sgml            |   7 +
 doc/src/sgml/ref/do.sgml                          |   7 +
 doc/src/sgml/spi.sgml                             | 219 ++++++++++++++++++++
 src/backend/commands/functioncmds.c               |  45 +++-
 src/backend/executor/spi.c                        | 112 ++++++++--
 src/backend/tcop/utility.c                        |   6 +-
 src/backend/utils/mmgr/portalmem.c                |  58 +++---
 src/include/commands/defrem.h                     |   4 +-
 src/include/executor/spi.h                        |   5 +
 src/include/executor/spi_priv.h                   |   4 +
 src/include/nodes/nodes.h                         |   3 +-
 src/include/nodes/parsenodes.h                    |   7 +
 src/include/utils/portal.h                        |   1 +
 src/pl/plperl/GNUmakefile                         |   2 +-
 src/pl/plperl/SPI.xs                              |  12 ++
 src/pl/plperl/expected/plperl_transaction.out     |  94 +++++++++
 src/pl/plperl/plperl.c                            |   6 +
 src/pl/plperl/sql/plperl_transaction.sql          |  88 ++++++++
 src/pl/plpgsql/src/pl_exec.c                      |  66 +++++-
 src/pl/plpgsql/src/pl_funcs.c                     |  44 ++++
 src/pl/plpgsql/src/pl_gram.y                      |  34 +++
 src/pl/plpgsql/src/pl_handler.c                   |   8 +
 src/pl/plpgsql/src/pl_scanner.c                   |   2 +
 src/pl/plpgsql/src/plpgsql.h                      |  22 +-
 src/pl/plpython/Makefile                          |   1 +
 src/pl/plpython/expected/plpython_test.out        |   4 +-
 src/pl/plpython/expected/plpython_transaction.out | 104 ++++++++++
 src/pl/plpython/plpy_main.c                       |   7 +-
 src/pl/plpython/plpy_plpymodule.c                 |  28 +++
 src/pl/plpython/sql/plpython_transaction.sql      |  87 ++++++++
 src/pl/tcl/Makefile                               |   2 +-
 src/pl/tcl/expected/pltcl_transaction.out         |  63 ++++++
 src/pl/tcl/pltcl.c                                |  44 ++++
 src/pl/tcl/sql/pltcl_transaction.sql              |  60 ++++++
 src/test/regress/expected/plpgsql.out             | 241 ++++++++++++++++++++++
 src/test/regress/sql/plpgsql.sql                  | 214 +++++++++++++++++++
 41 files changed, 1835 insertions(+), 102 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 100162dead..82ddf26606 100644
--- a/doc/src/sgml/plperl.sgml
+++ b/doc/src/sgml/plperl.sgml
@@ -661,6 +661,55 @@ <title>Database Access from PL/Perl</title>
     </para>
     </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term>
+      <literal><function>spi_commit()</function></literal>
+      <indexterm>
+       <primary>spi_commit</primary>
+       <secondary>in PL/Perl</secondary>
+     </indexterm>
+     </term>
+     <term>
+      <literal><function>spi_rollback()</function></literal>
+      <indexterm>
+       <primary>spi_rollback</primary>
+       <secondary>in PL/Perl</secondary>
+      </indexterm>
+     </term>
+     <listitem>
+      <para>
+       Commit or roll back the current transaction.  This can only be called
+       in a procedure or anonymous code block called from the top level.
+       (Note that it is not possible to run the SQL
+       commands <command>COMMIT</command> or <command>ROLLBACK</command>
+       via <function>spi_exec_query</function> or similar.  It has to be done
+       using these functions.)  After a transaction is ended, a new
+       transaction is automatically started, so there is no separate function
+       for that.
+      </para>
+
+      <para>
+       Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
  </sect2>
 
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 7d23ed437e..285467343a 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3449,6 +3449,48 @@ <title>Looping Through a Cursor's Result</title>
 
   </sect1>
 
+  <sect1 id="plpgsql-transactions">
+   <title>Transaction Management</title>
+
+   <para>
+    In procedures invoked by the <command>CALL</command> command from the top
+    level as well as in anonymous code blocks called from the top level, it is
+    possible to end transactions using the commands <command>COMMIT</command>
+    and <command>ROLLBACK</command>.  A new transaction is started
+    automatically after a transaction is ended using these commands, so there
+    is no separate <command>START TRANSACTION</command> command.  (And of
+    course, <command>BEGIN</command> and <command>END</command> have different
+    meanings in PL/pgSQL.)
+   </para>
+
+   <para>
+    Here is a simple example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+</programlisting>
+   </para>
+
+   <para>
+    Transactions cannot be ended inside loops through query results or inside
+    blocks with exception handlers.
+   </para>
+  </sect1>
+
   <sect1 id="plpgsql-errors-and-messages">
    <title>Errors and Messages</title>
 
@@ -5432,14 +5474,13 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 <programlisting>
 CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS
     a_running_job_count INTEGER;
-    PRAGMA AUTONOMOUS_TRANSACTION; -- <co id="co.plpgsql-porting-pragma"/>
 BEGIN
-    LOCK TABLE cs_jobs IN EXCLUSIVE MODE; -- <co id="co.plpgsql-porting-locktable"/>
+    LOCK TABLE cs_jobs IN EXCLUSIVE MODE;
 
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
-        COMMIT; -- free lock <co id="co.plpgsql-porting-commit"/>
+        COMMIT; -- free lock
         raise_application_error(-20000,
                  'Unable to create a new job: a job is currently running.');
     END IF;
@@ -5459,45 +5500,11 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 </programlisting>
    </para>
 
-   <para>
-    Procedures like this can easily be converted into <productname>PostgreSQL</productname>
-    functions returning <type>void</type>. This procedure in
-    particular is interesting because it can teach us some things:
-
-    <calloutlist>
-     <callout arearefs="co.plpgsql-porting-pragma">
-      <para>
-       There is no <literal>PRAGMA</literal> statement in <productname>PostgreSQL</productname>.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-locktable">
-      <para>
-       If you do a <command>LOCK TABLE</command> in <application>PL/pgSQL</application>,
-       the lock will not be released until the calling transaction is
-       finished.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-commit">
-      <para>
-       You cannot issue <command>COMMIT</command> in a
-       <application>PL/pgSQL</application> function.  The function is
-       running within some outer transaction and so <command>COMMIT</command>
-       would imply terminating the function's execution.  However, in
-       this particular case it is not necessary anyway, because the lock
-       obtained by the <command>LOCK TABLE</command> will be released when
-       we raise an error.
-      </para>
-     </callout>
-    </calloutlist>
-   </para>
-
    <para>
     This is how we could port this procedure to <application>PL/pgSQL</application>:
 
 <programlisting>
-CREATE OR REPLACE FUNCTION cs_create_job(v_job_id integer) RETURNS void AS $$
+CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id integer) AS $$
 DECLARE
     a_running_job_count integer;
 BEGIN
@@ -5506,6 +5513,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
+        COMMIT; -- free lock
         RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; -- <co id="co.plpgsql-porting-raise"/>
     END IF;
 
@@ -5518,6 +5526,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
         WHEN unique_violation THEN -- <co id="co.plpgsql-porting-exception"/>
             -- don't worry if it already exists
     END;
+    COMMIT;
 END;
 $$ LANGUAGE plpgsql;
 </programlisting>
@@ -5541,12 +5550,6 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
       </para>
      </callout>
     </calloutlist>
-
-    The main functional difference between this procedure and the
-    Oracle equivalent is that the exclusive lock on the <literal>cs_jobs</literal>
-    table will be held until the calling transaction completes.  Also, if
-    the caller later aborts (for example due to an error), the effects of
-    this procedure will be rolled back.
    </para>
    </example>
   </sect2>
diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 0dbeee1fa2..76cc0fc314 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -1370,6 +1370,44 @@ <title>Older Python Versions</title>
   </sect2>
  </sect1>
 
+ <sect1 id="plpython-transactions">
+  <title>Transaction Management</title>
+
+  <para>
+   In a procedure called from the top level or an anonymous code block called
+   from the top level it is possible to control transactions.  To commit the
+   current transaction, call <literal>plpy.commit()</literal>.  To roll back
+   the current transaction, call <literal>plpy.rollback()</literal>.  (Note
+   that it is not possible to run the SQL commands <command>COMMIT</command>
+   or <command>ROLLBACK</command> via <function>plpy.execute</function> or
+   similar.  It has to be done using these functions.)  After a transaction is
+   ended, a new transaction is automatically started, so there is no separate
+   function for that.
+  </para>
+
+  <para>
+   Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+</programlisting>
+  </para>
+
+  <para>
+   Transactions cannot be ended when an explicit subtransaction is active.
+  </para>
+ </sect1>
+
  <sect1 id="plpython-util">
   <title>Utility Functions</title>
   <para>
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml
index 8018783b0a..f7604d4787 100644
--- a/doc/src/sgml/pltcl.sgml
+++ b/doc/src/sgml/pltcl.sgml
@@ -1002,6 +1002,47 @@ <title>Explicit Subtransactions in PL/Tcl</title>
     </para>
    </sect1>
 
+   <sect1 id="pltcl-transactions">
+    <title>Transaction Management</title>
+
+    <para>
+     In a procedure called from the top level or an anonymous code block
+     called from the top level it is possible to control transactions.  To
+     commit the current transaction, call the <literal>commit</literal>
+     command.  To roll back the current transaction, call
+     the <literal>rollback</literal> command.  (Note that it is not possible
+     to run the SQL commands <command>COMMIT</command>
+     or <command>ROLLBACK</command> via <function>spi_exec</function> or
+     similar.  It has to be done using these functions.)  After a transaction
+     is ended, a new transaction is automatically started, so there is no
+     separate command for that.
+    </para>
+
+    <para>
+     Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i &lt; 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+    </para>
+
+    <para>
+     Transactions cannot be ended when an explicit subtransaction is active.
+    </para>
+   </sect1>
+
    <sect1 id="pltcl-config">
     <title>PL/Tcl Configuration</title>
 
diff --git a/doc/src/sgml/ref/call.sgml b/doc/src/sgml/ref/call.sgml
index 2741d8d15e..03da4518ee 100644
--- a/doc/src/sgml/ref/call.sgml
+++ b/doc/src/sgml/ref/call.sgml
@@ -70,6 +70,13 @@ <title>Notes</title>
   <para>
    To call a function (not a procedure), use <command>SELECT</command> instead.
   </para>
+
+  <para>
+   If <command>CALL</command> is executed in a transaction block, then the
+   called procedure cannot execute transaction control statements.
+   Transaction control statements are only allowed if <command>CALL</command>
+   is executed in its own transaction.
+  </para>
  </refsect1>
 
  <refsect1>
diff --git a/doc/src/sgml/ref/create_procedure.sgml b/doc/src/sgml/ref/create_procedure.sgml
index d712043824..bbf8b03d04 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -228,6 +228,13 @@ <title>Parameters</title>
        procedure exit, unless the current transaction is rolled back.
       </para>
 
+      <para>
+       If a <literal>SET</literal> clause is attached to a procedure, then
+       that procedure cannot execute transaction control statements (for
+       example, <command>COMMIT</command> and <command>ROLLBACK</command>,
+       depending on the language).
+      </para>
+
       <para>
        See <xref linkend="sql-set"/> and
        <xref linkend="runtime-config"/>
diff --git a/doc/src/sgml/ref/do.sgml b/doc/src/sgml/ref/do.sgml
index 061218b135..b9a6f9a6fd 100644
--- a/doc/src/sgml/ref/do.sgml
+++ b/doc/src/sgml/ref/do.sgml
@@ -91,6 +91,13 @@ <title>Notes</title>
    This is the same privilege requirement as for creating a function
    in the language.
   </para>
+
+  <para>
+   If <command>DO</command> is executed in a transaction block, then the
+   procedure code cannot execute transaction control statements.  Transaction
+   control statements are only allowed if <command>DO</command> is executed in
+   its own transaction.
+  </para>
  </refsect1>
 
  <refsect1 id="sql-do-examples">
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 350f0863e9..6df8f8368b 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -4325,6 +4325,225 @@ <title>Return Value</title>
 
  </sect1>
 
+ <sect1 id="spi-transaction">
+  <title>Transaction Management</title>
+
+  <para>
+   It is not possible to run transaction control commands such
+   as <command>COMMIT</command> and <command>ROLLBACK</command> through SPI
+   functions such as <function>SPI_execute</function>.  There are, however,
+   separate interface functions that allow transaction control through SPI.
+  </para>
+
+  <para>
+   It is not generally safe and sensible to start and end transactions in
+   arbitrary user-defined SQL-callable functions without taking into account
+   the context in which they are called.  For example, a transaction boundary
+   in the middle of a function that is part of a complex SQL expression that
+   is part of some SQL command will probably result in obscure internal errors
+   or crashes.  The interface functions presented here are primarily intended
+   to be used by procedural language implementations to support transaction
+   management in procedures that are invoked by the <command>CALL</command>
+   command, taking the context of the <command>CALL</command> invocation into
+   account.  SPI procedures implemented in C can implement the same logic, but
+   the details of that are beyond the scope of this documentation.
+  </para>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-commit">
+ <indexterm><primary>SPI_commit</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_commit</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_commit</refname>
+  <refpurpose>commit the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_commit(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_commit</function> commits the current transaction.  It is
+   approximately equivalent to running the SQL
+   command <command>COMMIT</command>.  After a transaction is committed, a new
+   transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-rollback">
+ <indexterm><primary>SPI_rollback</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_rollback</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_rollback</refname>
+  <refpurpose>abort the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_rollback(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_rollback</function> rolls back the current transaction.  It
+   is approximately equivalent to running the SQL
+   command <command>ROLLBACK</command>.  After a transaction is rolled back, a
+   new transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-set-nonatomic">
+ <indexterm><primary>SPI_set_nonatomic</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_set_nonatomic</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_set_nonatomic</refname>
+  <refpurpose>makes current SPI connection nonatomic</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_set_nonatomic(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_set_nonatomic</function> sets the current SPI connection to
+   be <firstterm>nonatomic</firstterm>, which means that transaction control
+   calls <function>SPI_commit</function>, <function>SPI_rollback</function>,
+   and <function>SPI_start_transaction</function> are allowed.  Otherwise,
+   calling these functions will result in an immediate
+   error.  <function>SPI_set_nonatomic</function> has to be called
+   after <function>SPI_connect</function> and its effects are canceled by the
+   corresponding <function>SPI_finish</function>, but it can be called at any
+   point in between.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-start-transaction">
+ <indexterm><primary>SPI_start_transaction</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_start_transaction</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_start_transaction</refname>
+  <refpurpose>start a new transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+int SPI_start_transaction(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_start_transaction</function> starts a new transaction.  It
+   can only be called after <function>SPI_commit</function>
+   or <function>SPI_rollback</function>, as there is no transaction active at
+   that point.  Normally, when an SPI procedure is called, there is already a
+   transaction active, so attempting to start another one before closing out
+   the current one will result in an error.
+  </para>
+
+  <para>
+   Before this function can be
+   executed, <function>SPI_set_nonatomic</function> has to be called for the
+   current SPI connection.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Return Value</title>
+
+  <para>
+   0 on success
+  </para>
+ </refsect1>
+</refentry>
+
+ </sect1>
+
  <sect1 id="spi-visibility">
   <title>Visibility of Data Changes</title>
 
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 2a9c90133d..4101817c5e 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2138,7 +2139,7 @@ IsThereFunctionInNamespace(const char *proname, int pronargs,
  *		Execute inline procedural-language code
  */
 void
-ExecuteDoStmt(DoStmt *stmt)
+ExecuteDoStmt(DoStmt *stmt, bool atomic)
 {
 	InlineCodeBlock *codeblock = makeNode(InlineCodeBlock);
 	ListCell   *arg;
@@ -2200,6 +2201,7 @@ ExecuteDoStmt(DoStmt *stmt)
 	codeblock->langOid = HeapTupleGetOid(languageTuple);
 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
 	codeblock->langIsTrusted = languageStruct->lanpltrusted;
+	codeblock->atomic = atomic;
 
 	if (languageStruct->lanpltrusted)
 	{
@@ -2236,9 +2238,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2249,6 +2270,8 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
+	HeapTuple	tp;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2284,8 +2307,24 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
+
+	/*
+	 * If proconfig is set we can't allow transaction commands because of the
+	 * way the GUC stacking works: The transaction boundary would have to pop
+	 * the proconfig setting off the stack.  That restriction could be lifted
+	 * by redesigning the GUC nesting mechanism a bit.
+	 */
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
+	if (!heap_attisnull(tp, Anum_pg_proc_proconfig))
+		callcontext->atomic = true;
+	ReleaseSysCache(tp);
+
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 2da1cac3e2..57c689c60b 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -92,7 +92,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,6 +124,7 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = true;	/* until told otherwise */
 
 	/*
 	 * Create memory contexts for this procedure
@@ -133,10 +134,10 @@ SPI_connect(void)
 	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
 	 * because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -145,6 +146,17 @@ SPI_connect(void)
 	return SPI_OK_CONNECT;
 }
 
+int
+SPI_set_nonatomic(void)
+{
+	if (_SPI_current == NULL)
+		return SPI_ERROR_UNCONNECTED;
+
+	_SPI_current->atomic = false;
+
+	return SPI_OK_CONNECT;
+}
+
 int
 SPI_finish(void)
 {
@@ -158,8 +170,6 @@ SPI_finish(void)
 	MemoryContextSwitchTo(_SPI_current->savedcxt);
 
 	/* Release memory used in procedure call (including tuptables) */
-	MemoryContextDelete(_SPI_current->execCxt);
-	_SPI_current->execCxt = NULL;
 	MemoryContextDelete(_SPI_current->procCxt);
 	_SPI_current->procCxt = NULL;
 
@@ -181,12 +191,87 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+int
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+	return 0;
+}
+
+int
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/*
+	 * This restriction is particular to PLs implemented on top of SPI.  They
+	 * use subtransactions to establish exception blocks that are supposed to
+	 * be rolled back together if there is an error.  Terminating the
+	 * top-level transaction in such a block violates that idea.  A future PL
+	 * implementation might have different ideas about this, in which case
+	 * this restriction would have to be refined or the check possibly be
+	 * moved out of SPI into the PLs.
+	 */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot commit while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
+int
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/* see under SPI_commit() */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot roll back while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+
+	return 0;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,21 +309,10 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
-		found = true;
+		if (connection->internal_xact)
+			break;
 
-		/*
-		 * Release procedure memory explicitly (see note in SPI_connect)
-		 */
-		if (connection->execCxt)
-		{
-			MemoryContextDelete(connection->execCxt);
-			connection->execCxt = NULL;
-		}
-		if (connection->procCxt)
-		{
-			MemoryContextDelete(connection->procCxt);
-			connection->procCxt = NULL;
-		}
+		found = true;
 
 		/*
 		 * Pop the stack entry and reset global variables.  Unlike
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4da1f8f643..35f018c8da 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -529,7 +529,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_DoStmt:
-			ExecuteDoStmt((DoStmt *) parsetree);
+			ExecuteDoStmt((DoStmt *) parsetree,
+						  (context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -658,7 +659,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree),
+							(context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index d03b779407..d750425852 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -736,11 +736,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -754,17 +751,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -799,14 +785,6 @@ AtAbort_Portals(void)
 		 * PortalDrop.
 		 */
 		portal->resowner = NULL;
-
-		/*
-		 * Although we can't delete the portal data structure proper, we can
-		 * release any memory in subsidiary contexts, such as executor state.
-		 * The cleanup hook was the last thing that might have needed data
-		 * there.
-		 */
-		MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
 	}
 }
 
@@ -826,6 +804,19 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 *
+		 * Note however that any resource owner attached to such a portal is
+		 * still going to go away, so don't leave a dangling pointer.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+		{
+			portal->resowner = NULL;
+			continue;
+		}
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
@@ -1155,3 +1146,22 @@ ThereAreNoReadyPortals(void)
 
 	return true;
 }
+
+bool
+ThereArePinnedPortals(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->portalPinned)
+			return true;
+	}
+
+	return false;
+}
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 52cbf61ccb..b03f5b6a95 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -58,8 +58,8 @@ extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
-extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteDoStmt(DoStmt *stmt, bool atomic);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index acade7e92e..e38158c54e 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -78,6 +78,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_set_nonatomic(void);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +157,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern int	SPI_start_transaction(void);
+extern int	SPI_commit(void);
+extern int	SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 8fae755418..9dc8af22e4 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index c5b5115f5b..6dcd51e958 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -500,7 +500,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in nodes/parsenodes.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2eaa6b2774..cb1afd68f8 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2803,6 +2803,7 @@ typedef struct InlineCodeBlock
 	char	   *source_text;	/* source text of anonymous code block */
 	Oid			langOid;		/* OID of selected language */
 	bool		langIsTrusted;	/* trusted property of the language */
+	bool		atomic;			/* atomic execution context */
 } InlineCodeBlock;
 
 /* ----------------------
@@ -2815,6 +2816,12 @@ typedef struct CallStmt
 	FuncCall   *funccall;
 } CallStmt;
 
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
 /* ----------------------
  *		Alter Object Rename Statement
  * ----------------------
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index cb6f00081d..cdbe7323d8 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -237,5 +237,6 @@ extern PlannedStmt *PortalGetPrimaryStmt(Portal portal);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
 extern bool ThereAreNoReadyPortals(void);
+extern bool ThereArePinnedPortals(void);
 
 #endif							/* PORTAL_H */
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..dc9ddedc8f 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,17 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		SPI_commit();
+		SPI_start_transaction();
+
+void
+spi_spi_rollback()
+	CODE:
+		SPI_rollback();
+		SPI_start_transaction();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..f7378ce600
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,94 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+-- FIXME
+--SELECT transaction_test3();
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+-- FIXME
+--SELECT transaction_test4();
+DROP TABLE test1;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 9f5313235f..68592033f7 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -1931,6 +1931,8 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		if (SPI_connect() != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
+		if (!codeblock->atomic)
+			SPI_set_nonatomic();
 
 		select_perl_context(desc.lanpltrusted);
 
@@ -2409,6 +2411,10 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 	current_call_data->prodesc = prodesc;
 	increment_prodesc_refcount(prodesc);
 
+	if (prodesc->result_oid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	/* Set a callback for error reporting */
 	pl_error_context.callback = plperl_exec_callback;
 	pl_error_context.previous = error_context_stack;
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..5f15691cfc
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,88 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+-- FIXME
+--SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+
+-- FIXME
+--SELECT transaction_test4();
+
+
+DROP TABLE test1;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index ec480cb0ba..b8b0df21de 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -215,6 +215,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1652,6 +1656,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4356,6 +4368,57 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	/*
+	 * XXX This could be implemented by converting the pinned portals to
+	 * holdable ones and organizing the cleanup separately.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("committing inside a cursor loop is not supported")));
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	/*
+	 * Unlike the COMMIT case above, this might not make sense at all,
+	 * especially if the query driving the cursor loop has side effects.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot abort transaction inside a cursor loop")));
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6857,8 +6920,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 */
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
-		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 23f54e1c21..a3a45916d1 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1243,6 +1273,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 94f1f58593..e661750176 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -199,6 +199,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -261,6 +262,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -326,6 +328,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -898,6 +901,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2174,6 +2181,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2410,6 +2442,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2461,6 +2494,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 1ebb7a7b5e..6857b0375e 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -255,7 +255,12 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
+			if (func->fn_rettype == InvalidOid &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+				SPI_set_nonatomic();
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -304,6 +309,9 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
+	if (!codeblock->atomic)
+		SPI_set_nonatomic();
+
 	/* Compile the anonymous code block */
 	func = plpgsql_compile_inline(codeblock->source_text);
 
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index 553be8c93c..a172031db2 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 2b19948562..8494a4374d 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..39b994f446 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -48,6 +48,7 @@ select module_contents();
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,11 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
  subtransaction
  warning
-(18 rows)
+(20 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..ff07bce193
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,104 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+SELECT transaction_test4();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test4", line 2, in <module>
+    plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+PL/Python function "transaction_test4"
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+WARNING:  forcibly aborting a subtransaction that has not been exited
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/Python anonymous code block
+DROP TABLE test1;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 695de30583..254ab37359 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -262,6 +262,9 @@ plpython_call_handler(PG_FUNCTION_ARGS)
 		else
 		{
 			proc = PLy_procedure_get(funcoid, InvalidOid, false);
+			if (proc->is_procedure &&
+				!castNode(CallContext, fcinfo->context)->atomic)
+					SPI_set_nonatomic();
 			exec_ctx->curr_proc = proc;
 			retval = PLy_exec_function(fcinfo, proc);
 		}
@@ -305,6 +308,8 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
 	if (SPI_connect() != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
+	if (!codeblock->atomic)
+		SPI_set_nonatomic();
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
 	MemSet(&flinfo, 0, sizeof(flinfo));
@@ -435,7 +440,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23f99e20ca..b9b9e423a7 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -41,6 +43,8 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +99,12 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +587,21 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..0656aa1458
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,87 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+
+SELECT transaction_test4();
+
+
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..6ce900027c
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,63 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index e0792d93e1..0571755b4f 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -312,6 +312,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +528,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -812,6 +820,10 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid, InvalidOid,
 									 false, pltrusted);
 
+	if (prodesc->result_typid == InvalidOid &&
+		!castNode(CallContext, fcinfo->context)->atomic)
+		SPI_set_nonatomic();
+
 	call_state->prodesc = prodesc;
 	prodesc->fn_refcount++;
 
@@ -2935,6 +2947,38 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..14aed5844a
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,60 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index d6e5bc3353..824977afc5 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -6077,7 +6077,248 @@ SELECT * FROM proc_test1;
  55
 (1 row)
 
+TRUNCATE proc_test1;
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL test_proc_transaction1();
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+TRUNCATE proc_test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM proc_test1;
+ a 
+---
+ 0
+ 2
+ 4
+ 6
+ 8
+(5 rows)
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL test_proc_transaction1();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction1() line 6 at COMMIT
+COMMIT;
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+COMMIT;
+TRUNCATE proc_test1;
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT test_proc_transaction2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction2() line 6 at COMMIT
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+SELECT test_proc_transaction3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction1() line 6 at COMMIT
+SQL statement "CALL test_proc_transaction1()"
+PL/pgSQL function test_proc_transaction3() line 3 at SQL statement
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION test_proc_transaction4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+SELECT test_proc_transaction4();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+SQL statement "DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$"
+PL/pgSQL function test_proc_transaction4() line 3 at EXECUTE
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE test_proc_transaction5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+CALL test_proc_transaction5();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function test_proc_transaction5() line 3 at COMMIT
+-- commit inside cursor loop
+CREATE TABLE proc_test2 (x int);
+INSERT INTO proc_test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE proc_test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM proc_test2 ORDER BY x LOOP
+        INSERT INTO proc_test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+ERROR:  committing inside a cursor loop is not supported
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at COMMIT
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE proc_test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM proc_test2 ORDER BY x LOOP
+        INSERT INTO proc_test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+ERROR:  cannot abort transaction inside a cursor loop
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at ROLLBACK
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- commit inside block with exception handler
+TRUNCATE proc_test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO proc_test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO proc_test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at COMMIT
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- rollback inside block with exception handler
+TRUNCATE proc_test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO proc_test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO proc_test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot roll back while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at ROLLBACK
+SELECT * FROM proc_test1;
+ a 
+---
+(0 rows)
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE proc_test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (1);
+    INSERT INTO proc_test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+ERROR:  duplicate key value violates unique constraint "proc_test3_y_key"
+DETAIL:  Key (y)=(1) already exists.
+CONTEXT:  PL/pgSQL function inline_code_block line 9 at COMMIT
+SELECT * FROM proc_test3;
+ y 
+---
+ 1
+(1 row)
+
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 DROP TABLE proc_test1;
+DROP TABLE proc_test2;
+DROP TABLE proc_test3;
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index 1c355132b7..3cd61feb70 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -4864,8 +4864,222 @@ CREATE PROCEDURE test_proc3(x int)
 SELECT * FROM proc_test1;
 
 
+TRUNCATE proc_test1;
+
+CREATE PROCEDURE test_proc_transaction1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL test_proc_transaction1();
+
+SELECT * FROM proc_test1;
+
+
+TRUNCATE proc_test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM proc_test1;
+
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL test_proc_transaction1();
+COMMIT;
+
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+COMMIT;
+
+
+TRUNCATE proc_test1;
+
+-- not allowed in a function
+CREATE FUNCTION test_proc_transaction2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO proc_test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT test_proc_transaction2();
+
+SELECT * FROM proc_test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION test_proc_transaction3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL test_proc_transaction1();
+    RETURN 1;
+END;
+$$;
+
+SELECT test_proc_transaction3();
+
+SELECT * FROM proc_test1;
+
+
+-- DO block inside function
+CREATE FUNCTION test_proc_transaction4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+
+SELECT test_proc_transaction4();
+
+
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE test_proc_transaction5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+
+CALL test_proc_transaction5();
+
+
+-- commit inside cursor loop
+CREATE TABLE proc_test2 (x int);
+INSERT INTO proc_test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE proc_test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM proc_test2 ORDER BY x LOOP
+        INSERT INTO proc_test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM proc_test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE proc_test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM proc_test2 ORDER BY x LOOP
+        INSERT INTO proc_test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM proc_test1;
+
+
+-- commit inside block with exception handler
+TRUNCATE proc_test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO proc_test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO proc_test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM proc_test1;
+
+
+-- rollback inside block with exception handler
+TRUNCATE proc_test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO proc_test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO proc_test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM proc_test1;
+
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE proc_test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (1);
+    INSERT INTO proc_test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO proc_test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+
+SELECT * FROM proc_test3;
+
+
 DROP PROCEDURE test_proc1;
 DROP PROCEDURE test_proc2;
 DROP PROCEDURE test_proc3;
+DROP PROCEDURE test_proc_transaction1;
 
 DROP TABLE proc_test1;
+DROP TABLE proc_test2;
+DROP TABLE proc_test3;

base-commit: 979a36c3894db0a4b0d6b4b20fc861a0bbe3271c
-- 
2.15.1

From 984d2974311ce6d8760ec3d59af66363cc53fc6d Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Wed, 20 Dec 2017 09:25:45 -0500
Subject: [PATCH v5] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.

- SPI

Add a new function SPI_connect_ext() that is like SPI_connect() but
allows passing option flags.  The only option flag right now is
SPI_OPT_NONATOMIC.  A nonatomic SPI connection can execute transaction
control commands, otherwise it's not allowed.  This is meant to be
passed down from CALL and DO statements which themselves know in which
context they are called.  A nonatomic SPI connection uses different
memory management.  A normal SPI connection allocates its memory in
TopTransactionContext.  For nonatomic connections we use PortalContext
instead.  As the comment in SPI_connect_ext() (previously SPI_connect())
indicates, one could potentially use PortalContext in all cases, but it
seems safest to leave the existing uses alone, because this stuff is
complicated enough already.

SPI also gets new functions SPI_start_transaction(), SPI_commit(), and
SPI_rollback(), which can be used by PLs to implement their transaction
control logic.

- portalmem.c

Some adjustments were made in the code that cleans up portals at
transaction abort.  The portal code could already handle a command
*committing* a transaction and continuing (e.g., VACUUM), but it was not
quite prepared for a command *aborting* a transaction and continuing.

In AtAbort_Portals(), remove the code that marks an active portal as
failed.  As the comment there already predicted, this doesn't work if
the running command wants to keep running after transaction abort.  And
it's actually not necessary, because pquery.c is careful to run all
portal code in a PG_TRY block and explicitly runs MarkPortalFailed() if
there is an exception.  So the code in AtAbort_Portals() is never used
anyway.

In AtAbort_Portals() and AtCleanup_Portals(), we need to be careful not
to clean up active portals too much.  This mirrors similar code in
PreCommit_Portals().

- PL/Perl

Gets new functions spi_commit() and spi_rollback()

- PL/pgSQL

Gets new commands COMMIT and ROLLBACK.

Update the PL/SQL porting example in the documentation to reflect that
transactions are now possible in procedures.

- PL/Python

Gets new functions plpy.commit and plpy.rollback.

- PL/Tcl

Gets new commands commit and rollback.
---
 doc/src/sgml/plperl.sgml                           |  49 +++++
 doc/src/sgml/plpgsql.sgml                          |  91 ++++----
 doc/src/sgml/plpython.sgml                         |  39 ++++
 doc/src/sgml/pltcl.sgml                            |  41 ++++
 doc/src/sgml/ref/call.sgml                         |   7 +
 doc/src/sgml/ref/create_procedure.sgml             |   7 +
 doc/src/sgml/ref/do.sgml                           |   7 +
 doc/src/sgml/spi.sgml                              | 177 +++++++++++++++
 src/backend/commands/functioncmds.c                |  45 +++-
 src/backend/executor/spi.c                         |  99 ++++++++-
 src/backend/tcop/utility.c                         |   6 +-
 src/backend/utils/mmgr/portalmem.c                 |  49 +++--
 src/include/commands/defrem.h                      |   4 +-
 src/include/executor/spi.h                         |   7 +
 src/include/executor/spi_priv.h                    |   4 +
 src/include/nodes/nodes.h                          |   3 +-
 src/include/nodes/parsenodes.h                     |   7 +
 src/include/utils/portal.h                         |   1 +
 src/pl/plperl/GNUmakefile                          |   2 +-
 src/pl/plperl/SPI.xs                               |  10 +
 src/pl/plperl/expected/plperl_transaction.out      | 132 +++++++++++
 src/pl/plperl/plperl.c                             |  59 ++++-
 src/pl/plperl/plperl.h                             |   2 +
 src/pl/plperl/sql/plperl_transaction.sql           | 122 +++++++++++
 src/pl/plpgsql/src/Makefile                        |   2 +-
 .../plpgsql/src/expected/plpgsql_transaction.out   | 241 +++++++++++++++++++++
 src/pl/plpgsql/src/pl_exec.c                       |  66 +++++-
 src/pl/plpgsql/src/pl_funcs.c                      |  44 ++++
 src/pl/plpgsql/src/pl_gram.y                       |  34 +++
 src/pl/plpgsql/src/pl_handler.c                    |  11 +-
 src/pl/plpgsql/src/pl_scanner.c                    |   2 +
 src/pl/plpgsql/src/plpgsql.h                       |  22 +-
 src/pl/plpgsql/src/sql/plpgsql_transaction.sql     | 215 ++++++++++++++++++
 src/pl/plpython/Makefile                           |   1 +
 src/pl/plpython/expected/plpython_test.out         |   4 +-
 src/pl/plpython/expected/plpython_transaction.out  | 144 ++++++++++++
 src/pl/plpython/plpy_main.c                        |  11 +-
 src/pl/plpython/plpy_plpymodule.c                  |  39 ++++
 src/pl/plpython/sql/plpython_transaction.sql       | 117 ++++++++++
 src/pl/tcl/Makefile                                |   2 +-
 src/pl/tcl/expected/pltcl_transaction.out          | 100 +++++++++
 src/pl/tcl/pltcl.c                                 |  47 +++-
 src/pl/tcl/sql/pltcl_transaction.sql               |  98 +++++++++
 43 files changed, 2078 insertions(+), 92 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpgsql/src/expected/plpgsql_transaction.out
 create mode 100644 src/pl/plpgsql/src/sql/plpgsql_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 100162dead..9acd41310f 100644
--- a/doc/src/sgml/plperl.sgml
+++ b/doc/src/sgml/plperl.sgml
@@ -661,6 +661,55 @@ <title>Database Access from PL/Perl</title>
     </para>
     </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term>
+      <literal><function>spi_commit()</function></literal>
+      <indexterm>
+       <primary>spi_commit</primary>
+       <secondary>in PL/Perl</secondary>
+     </indexterm>
+     </term>
+     <term>
+      <literal><function>spi_rollback()</function></literal>
+      <indexterm>
+       <primary>spi_rollback</primary>
+       <secondary>in PL/Perl</secondary>
+      </indexterm>
+     </term>
+     <listitem>
+      <para>
+       Commit or roll back the current transaction.  This can only be called
+       in a procedure or anonymous code block (<command>DO</command> command)
+       called from the top level.  (Note that it is not possible to run the
+       SQL commands <command>COMMIT</command> or <command>ROLLBACK</command>
+       via <function>spi_exec_query</function> or similar.  It has to be done
+       using these functions.)  After a transaction is ended, a new
+       transaction is automatically started, so there is no separate function
+       for that.
+      </para>
+
+      <para>
+       Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
  </sect2>
 
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 7d23ed437e..00441af810 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3449,6 +3449,48 @@ <title>Looping Through a Cursor's Result</title>
 
   </sect1>
 
+  <sect1 id="plpgsql-transactions">
+   <title>Transaction Management</title>
+
+   <para>
+    In procedures invoked by the <command>CALL</command> command from the top
+    level as well as in anonymous code blocks (<command>DO</command> command)
+    called from the top level, it is possible to end transactions using the
+    commands <command>COMMIT</command> and <command>ROLLBACK</command>.  A new
+    transaction is started automatically after a transaction is ended using
+    these commands, so there is no separate <command>START
+    TRANSACTION</command> command.  (Note that <command>BEGIN</command> and
+    <command>END</command> have different meanings in PL/pgSQL.)
+   </para>
+
+   <para>
+    Here is a simple example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+</programlisting>
+   </para>
+
+   <para>
+    Transactions cannot be ended inside loops through query results or inside
+    blocks with exception handlers.
+   </para>
+  </sect1>
+
   <sect1 id="plpgsql-errors-and-messages">
    <title>Errors and Messages</title>
 
@@ -5432,14 +5474,13 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 <programlisting>
 CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS
     a_running_job_count INTEGER;
-    PRAGMA AUTONOMOUS_TRANSACTION; -- <co id="co.plpgsql-porting-pragma"/>
 BEGIN
-    LOCK TABLE cs_jobs IN EXCLUSIVE MODE; -- <co id="co.plpgsql-porting-locktable"/>
+    LOCK TABLE cs_jobs IN EXCLUSIVE MODE;
 
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
-        COMMIT; -- free lock <co id="co.plpgsql-porting-commit"/>
+        COMMIT; -- free lock
         raise_application_error(-20000,
                  'Unable to create a new job: a job is currently running.');
     END IF;
@@ -5459,45 +5500,11 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 </programlisting>
    </para>
 
-   <para>
-    Procedures like this can easily be converted into <productname>PostgreSQL</productname>
-    functions returning <type>void</type>. This procedure in
-    particular is interesting because it can teach us some things:
-
-    <calloutlist>
-     <callout arearefs="co.plpgsql-porting-pragma">
-      <para>
-       There is no <literal>PRAGMA</literal> statement in <productname>PostgreSQL</productname>.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-locktable">
-      <para>
-       If you do a <command>LOCK TABLE</command> in <application>PL/pgSQL</application>,
-       the lock will not be released until the calling transaction is
-       finished.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-commit">
-      <para>
-       You cannot issue <command>COMMIT</command> in a
-       <application>PL/pgSQL</application> function.  The function is
-       running within some outer transaction and so <command>COMMIT</command>
-       would imply terminating the function's execution.  However, in
-       this particular case it is not necessary anyway, because the lock
-       obtained by the <command>LOCK TABLE</command> will be released when
-       we raise an error.
-      </para>
-     </callout>
-    </calloutlist>
-   </para>
-
    <para>
     This is how we could port this procedure to <application>PL/pgSQL</application>:
 
 <programlisting>
-CREATE OR REPLACE FUNCTION cs_create_job(v_job_id integer) RETURNS void AS $$
+CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id integer) AS $$
 DECLARE
     a_running_job_count integer;
 BEGIN
@@ -5506,6 +5513,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
+        COMMIT; -- free lock
         RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; -- <co id="co.plpgsql-porting-raise"/>
     END IF;
 
@@ -5518,6 +5526,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
         WHEN unique_violation THEN -- <co id="co.plpgsql-porting-exception"/>
             -- don't worry if it already exists
     END;
+    COMMIT;
 END;
 $$ LANGUAGE plpgsql;
 </programlisting>
@@ -5541,12 +5550,6 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
       </para>
      </callout>
     </calloutlist>
-
-    The main functional difference between this procedure and the
-    Oracle equivalent is that the exclusive lock on the <literal>cs_jobs</literal>
-    table will be held until the calling transaction completes.  Also, if
-    the caller later aborts (for example due to an error), the effects of
-    this procedure will be rolled back.
    </para>
    </example>
   </sect2>
diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 0dbeee1fa2..8641038abe 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -1370,6 +1370,45 @@ <title>Older Python Versions</title>
   </sect2>
  </sect1>
 
+ <sect1 id="plpython-transactions">
+  <title>Transaction Management</title>
+
+  <para>
+   In a procedure called from the top level or an anonymous code block
+   (<command>DO</command> command) called from the top level it is possible to
+   control transactions.  To commit the current transaction, call
+   <literal>plpy.commit()</literal>.  To roll back the current transaction,
+   call <literal>plpy.rollback()</literal>.  (Note that it is not possible to
+   run the SQL commands <command>COMMIT</command> or
+   <command>ROLLBACK</command> via <function>plpy.execute</function> or
+   similar.  It has to be done using these functions.)  After a transaction is
+   ended, a new transaction is automatically started, so there is no separate
+   function for that.
+  </para>
+
+  <para>
+   Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+</programlisting>
+  </para>
+
+  <para>
+   Transactions cannot be ended when an explicit subtransaction is active.
+  </para>
+ </sect1>
+
  <sect1 id="plpython-util">
   <title>Utility Functions</title>
   <para>
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml
index 8018783b0a..a834ab8862 100644
--- a/doc/src/sgml/pltcl.sgml
+++ b/doc/src/sgml/pltcl.sgml
@@ -1002,6 +1002,47 @@ <title>Explicit Subtransactions in PL/Tcl</title>
     </para>
    </sect1>
 
+   <sect1 id="pltcl-transactions">
+    <title>Transaction Management</title>
+
+    <para>
+     In a procedure called from the top level or an anonymous code block
+     (<command>DO</command> command) called from the top level it is possible
+     to control transactions.  To commit the current transaction, call the
+     <literal>commit</literal> command.  To roll back the current transaction,
+     call the <literal>rollback</literal> command.  (Note that it is not
+     possible to run the SQL commands <command>COMMIT</command> or
+     <command>ROLLBACK</command> via <function>spi_exec</function> or similar.
+     It has to be done using these functions.)  After a transaction is ended,
+     a new transaction is automatically started, so there is no separate
+     command for that.
+    </para>
+
+    <para>
+     Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i &lt; 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+    </para>
+
+    <para>
+     Transactions cannot be ended when an explicit subtransaction is active.
+    </para>
+   </sect1>
+
    <sect1 id="pltcl-config">
     <title>PL/Tcl Configuration</title>
 
diff --git a/doc/src/sgml/ref/call.sgml b/doc/src/sgml/ref/call.sgml
index 2741d8d15e..03da4518ee 100644
--- a/doc/src/sgml/ref/call.sgml
+++ b/doc/src/sgml/ref/call.sgml
@@ -70,6 +70,13 @@ <title>Notes</title>
   <para>
    To call a function (not a procedure), use <command>SELECT</command> instead.
   </para>
+
+  <para>
+   If <command>CALL</command> is executed in a transaction block, then the
+   called procedure cannot execute transaction control statements.
+   Transaction control statements are only allowed if <command>CALL</command>
+   is executed in its own transaction.
+  </para>
  </refsect1>
 
  <refsect1>
diff --git a/doc/src/sgml/ref/create_procedure.sgml b/doc/src/sgml/ref/create_procedure.sgml
index d712043824..bbf8b03d04 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -228,6 +228,13 @@ <title>Parameters</title>
        procedure exit, unless the current transaction is rolled back.
       </para>
 
+      <para>
+       If a <literal>SET</literal> clause is attached to a procedure, then
+       that procedure cannot execute transaction control statements (for
+       example, <command>COMMIT</command> and <command>ROLLBACK</command>,
+       depending on the language).
+      </para>
+
       <para>
        See <xref linkend="sql-set"/> and
        <xref linkend="runtime-config"/>
diff --git a/doc/src/sgml/ref/do.sgml b/doc/src/sgml/ref/do.sgml
index 061218b135..b9a6f9a6fd 100644
--- a/doc/src/sgml/ref/do.sgml
+++ b/doc/src/sgml/ref/do.sgml
@@ -91,6 +91,13 @@ <title>Notes</title>
    This is the same privilege requirement as for creating a function
    in the language.
   </para>
+
+  <para>
+   If <command>DO</command> is executed in a transaction block, then the
+   procedure code cannot execute transaction control statements.  Transaction
+   control statements are only allowed if <command>DO</command> is executed in
+   its own transaction.
+  </para>
  </refsect1>
 
  <refsect1 id="sql-do-examples">
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 350f0863e9..10448922b1 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -64,6 +64,7 @@ <title>Interface Functions</title>
 
  <refentry id="spi-spi-connect">
   <indexterm><primary>SPI_connect</primary></indexterm>
+  <indexterm><primary>SPI_connect_ext</primary></indexterm>
 
   <refmeta>
    <refentrytitle>SPI_connect</refentrytitle>
@@ -72,12 +73,17 @@ <title>Interface Functions</title>
 
   <refnamediv>
    <refname>SPI_connect</refname>
+   <refname>SPI_connect_ext</refname>
    <refpurpose>connect a procedure to the SPI manager</refpurpose>
  </refnamediv>
 
  <refsynopsisdiv>
 <synopsis>
 int SPI_connect(void)
+</synopsis>
+
+ <synopsis>
+int SPI_connect_ext(int <parameter>options</parameter>)
 </synopsis>
  </refsynopsisdiv>
 
@@ -90,6 +96,31 @@ <title>Description</title>
    function if you want to execute commands through SPI.  Some utility
    SPI functions can be called from unconnected procedures.
   </para>
+
+  <para>
+   <function>SPI_connect_ext</function> does the same but has an argument that
+   allows passing option flags.  Currently, the following option values are
+   available:
+   <variablelist>
+    <varlistentry>
+     <term><symbol>SPI_OPT_NONATOMIC</symbol></term>
+     <listitem>
+      <para>
+       Sets the SPI connection to be <firstterm>nonatomic</firstterm>, which
+       means that transaction control calls <function>SPI_commit</function>,
+       <function>SPI_rollback</function>, and
+       <function>SPI_start_transaction</function> are allowed.  Otherwise,
+       calling these functions will result in an immediate error.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+
+  <para>
+   <literal>SPI_connect()</literal> is equivalent to
+   <literal>SPI_connect_ext(0)</literal>.
+  </para>
  </refsect1>
 
  <refsect1>
@@ -4325,6 +4356,152 @@ <title>Return Value</title>
 
  </sect1>
 
+ <sect1 id="spi-transaction">
+  <title>Transaction Management</title>
+
+  <para>
+   It is not possible to run transaction control commands such
+   as <command>COMMIT</command> and <command>ROLLBACK</command> through SPI
+   functions such as <function>SPI_execute</function>.  There are, however,
+   separate interface functions that allow transaction control through SPI.
+  </para>
+
+  <para>
+   It is not generally safe and sensible to start and end transactions in
+   arbitrary user-defined SQL-callable functions without taking into account
+   the context in which they are called.  For example, a transaction boundary
+   in the middle of a function that is part of a complex SQL expression that
+   is part of some SQL command will probably result in obscure internal errors
+   or crashes.  The interface functions presented here are primarily intended
+   to be used by procedural language implementations to support transaction
+   management in procedures that are invoked by the <command>CALL</command>
+   command, taking the context of the <command>CALL</command> invocation into
+   account.  SPI procedures implemented in C can implement the same logic, but
+   the details of that are beyond the scope of this documentation.
+  </para>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-commit">
+ <indexterm><primary>SPI_commit</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_commit</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_commit</refname>
+  <refpurpose>commit the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_commit(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_commit</function> commits the current transaction.  It is
+   approximately equivalent to running the SQL
+   command <command>COMMIT</command>.  After a transaction is committed, a new
+   transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-rollback">
+ <indexterm><primary>SPI_rollback</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_rollback</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_rollback</refname>
+  <refpurpose>abort the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_rollback(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_rollback</function> rolls back the current transaction.  It
+   is approximately equivalent to running the SQL
+   command <command>ROLLBACK</command>.  After a transaction is rolled back, a
+   new transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-start-transaction">
+ <indexterm><primary>SPI_start_transaction</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_start_transaction</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_start_transaction</refname>
+  <refpurpose>start a new transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_start_transaction(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_start_transaction</function> starts a new transaction.  It
+   can only be called after <function>SPI_commit</function>
+   or <function>SPI_rollback</function>, as there is no transaction active at
+   that point.  Normally, when an SPI procedure is called, there is already a
+   transaction active, so attempting to start another one before closing out
+   the current one will result in an error.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+ </sect1>
+
  <sect1 id="spi-visibility">
   <title>Visibility of Data Changes</title>
 
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 2a9c90133d..4101817c5e 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2138,7 +2139,7 @@ IsThereFunctionInNamespace(const char *proname, int pronargs,
  *		Execute inline procedural-language code
  */
 void
-ExecuteDoStmt(DoStmt *stmt)
+ExecuteDoStmt(DoStmt *stmt, bool atomic)
 {
 	InlineCodeBlock *codeblock = makeNode(InlineCodeBlock);
 	ListCell   *arg;
@@ -2200,6 +2201,7 @@ ExecuteDoStmt(DoStmt *stmt)
 	codeblock->langOid = HeapTupleGetOid(languageTuple);
 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
 	codeblock->langIsTrusted = languageStruct->lanpltrusted;
+	codeblock->atomic = atomic;
 
 	if (languageStruct->lanpltrusted)
 	{
@@ -2236,9 +2238,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2249,6 +2270,8 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
+	HeapTuple	tp;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2284,8 +2307,24 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
+
+	/*
+	 * If proconfig is set we can't allow transaction commands because of the
+	 * way the GUC stacking works: The transaction boundary would have to pop
+	 * the proconfig setting off the stack.  That restriction could be lifted
+	 * by redesigning the GUC nesting mechanism a bit.
+	 */
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
+	if (!heap_attisnull(tp, Anum_pg_proc_proconfig))
+		callcontext->atomic = true;
+	ReleaseSysCache(tp);
+
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index f3da2ddd08..c3d1f59010 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -82,6 +82,12 @@ static bool _SPI_checktuples(void);
 
 int
 SPI_connect(void)
+{
+	return SPI_connect_ext(0);
+}
+
+int
+SPI_connect_ext(int options)
 {
 	int			newdepth;
 
@@ -92,7 +98,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,19 +130,25 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = (options & SPI_OPT_NONATOMIC ? false : true);
+	_SPI_current->internal_xact = false;
 
 	/*
 	 * Create memory contexts for this procedure
 	 *
-	 * XXX it would be better to use PortalContext as the parent context, but
-	 * we may not be inside a portal (consider deferred-trigger execution).
-	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
-	 * because we clean up explicitly in AtEOSubXact_SPI().
+	 * In atomic contexts (the normal case), we use TopTransactionContext,
+	 * otherwise PortalContext, so that it lives across transaction
+	 * boundaries.
+	 *
+	 * XXX It could be better to use PortalContext as the parent context in
+	 * all cases, but we may not be inside a portal (consider deferred-trigger
+	 * execution).  Perhaps CurTransactionContext could be an option?  For now
+	 * it doesn't matter because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : _SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -181,12 +193,82 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+void
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+}
+
+void
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/*
+	 * This restriction is required by PLs implemented on top of SPI.  They
+	 * use subtransactions to establish exception blocks that are supposed to
+	 * be rolled back together if there is an error.  Terminating the
+	 * top-level transaction in such a block violates that idea.  A future PL
+	 * implementation might have different ideas about this, in which case
+	 * this restriction would have to be refined or the check possibly be
+	 * moved out of SPI into the PLs.
+	 */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot commit while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
+void
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/* see under SPI_commit() */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot roll back while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,6 +306,9 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
+		if (connection->internal_xact)
+			break;
+
 		found = true;
 
 		/*
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4da1f8f643..35f018c8da 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -529,7 +529,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_DoStmt:
-			ExecuteDoStmt((DoStmt *) parsetree);
+			ExecuteDoStmt((DoStmt *) parsetree,
+						  (context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -658,7 +659,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree),
+							(context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index d03b779407..a78e51c9d4 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -736,11 +736,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -754,17 +751,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -804,9 +790,10 @@ AtAbort_Portals(void)
 		 * Although we can't delete the portal data structure proper, we can
 		 * release any memory in subsidiary contexts, such as executor state.
 		 * The cleanup hook was the last thing that might have needed data
-		 * there.
+		 * there.  But leave active portals alone.
 		 */
-		MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
+		if (portal->status != PORTAL_ACTIVE)
+			MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
 	}
 }
 
@@ -826,6 +813,13 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+			continue;
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
@@ -1155,3 +1149,22 @@ ThereAreNoReadyPortals(void)
 
 	return true;
 }
+
+bool
+ThereArePinnedPortals(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->portalPinned)
+			return true;
+	}
+
+	return false;
+}
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 52cbf61ccb..b03f5b6a95 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -58,8 +58,8 @@ extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
-extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteDoStmt(DoStmt *stmt, bool atomic);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index acade7e92e..9c35e0f335 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -65,6 +65,8 @@ typedef struct _SPI_plan *SPIPlanPtr;
 #define SPI_OK_REL_UNREGISTER	16
 #define SPI_OK_TD_REGISTER		17
 
+#define SPI_OPT_NONATOMIC		(1 << 0)
+
 /* These used to be functions, now just no-ops for backwards compatibility */
 #define SPI_push()	((void) 0)
 #define SPI_pop()	((void) 0)
@@ -78,6 +80,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_connect_ext(int options);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +159,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern void SPI_start_transaction(void);
+extern void SPI_commit(void);
+extern void SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 8fae755418..9dc8af22e4 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index c5b5115f5b..6dcd51e958 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -500,7 +500,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in nodes/parsenodes.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2eaa6b2774..cb1afd68f8 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2803,6 +2803,7 @@ typedef struct InlineCodeBlock
 	char	   *source_text;	/* source text of anonymous code block */
 	Oid			langOid;		/* OID of selected language */
 	bool		langIsTrusted;	/* trusted property of the language */
+	bool		atomic;			/* atomic execution context */
 } InlineCodeBlock;
 
 /* ----------------------
@@ -2815,6 +2816,12 @@ typedef struct CallStmt
 	FuncCall   *funccall;
 } CallStmt;
 
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
 /* ----------------------
  *		Alter Object Rename Statement
  * ----------------------
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index cb6f00081d..cdbe7323d8 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -237,5 +237,6 @@ extern PlannedStmt *PortalGetPrimaryStmt(Portal portal);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
 extern bool ThereAreNoReadyPortals(void);
+extern bool ThereArePinnedPortals(void);
 
 #endif							/* PORTAL_H */
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..de5d812cbd 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,15 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		plperl_spi_commit();
+
+void
+spi_spi_rollback()
+	CODE:
+		plperl_spi_rollback();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..5ce33d9c7c
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,132 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination at line 5.
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination at line 5. at line 2.
+CONTEXT:  PL/Perl function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination at line 1. at line 2.
+CONTEXT:  PL/Perl function "transaction_test4"
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+(1 row)
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 41fd0ba421..b3f3b43f8d 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -1929,7 +1929,7 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		current_call_data = &this_call_data;
 
-		if (SPI_connect() != SPI_OK_CONNECT)
+		if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
 
 		select_perl_context(desc.lanpltrusted);
@@ -2396,13 +2396,18 @@ plperl_call_perl_event_trigger_func(plperl_proc_desc *desc,
 static Datum
 plperl_func_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	plperl_proc_desc *prodesc;
 	SV		   *perlret;
 	Datum		retval = 0;
 	ReturnSetInfo *rsi;
 	ErrorContextCallback pl_error_context;
 
-	if (SPI_connect() != SPI_OK_CONNECT)
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	prodesc = compile_plperl_function(fcinfo->flinfo->fn_oid, false, false);
@@ -3945,6 +3950,56 @@ plperl_spi_freeplan(char *query)
 	SPI_freeplan(plan);
 }
 
+void
+plperl_spi_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_commit();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
+void
+plperl_spi_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_rollback();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
 /*
  * Implementation of plperl's elog() function
  *
diff --git a/src/pl/plperl/plperl.h b/src/pl/plperl/plperl.h
index aac95f8d2c..dca34d5dbc 100644
--- a/src/pl/plperl/plperl.h
+++ b/src/pl/plperl/plperl.h
@@ -125,6 +125,8 @@ HV		   *plperl_spi_exec_prepared(char *, HV *, int, SV **);
 SV		   *plperl_spi_query_prepared(char *, int, SV **);
 void		plperl_spi_freeplan(char *);
 void		plperl_spi_cursor_close(char *);
+void		plperl_spi_commit(void);
+void		plperl_spi_rollback(void);
 char	   *plperl_sv_to_literal(SV *, char *);
 void		plperl_util_elog(int level, SV *msg);
 
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..081e03f238
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,122 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+
+SELECT transaction_test4();
+
+
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 76ac247e57..6d8df9a4a0 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -26,7 +26,7 @@ DATA = plpgsql.control plpgsql--1.0.sql plpgsql--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB)
 
-REGRESS = plpgsql_call
+REGRESS = plpgsql_call plpgsql_transaction
 
 all: all-lib
 
diff --git a/src/pl/plpgsql/src/expected/plpgsql_transaction.out b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
new file mode 100644
index 0000000000..8ec22c646c
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
@@ -0,0 +1,241 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+COMMIT;
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+COMMIT;
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test2() line 6 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+SQL statement "CALL transaction_test1()"
+PL/pgSQL function transaction_test3() line 3 at SQL statement
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+SQL statement "DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$"
+PL/pgSQL function transaction_test4() line 3 at EXECUTE
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+CALL transaction_test5();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test5() line 3 at COMMIT
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+ERROR:  committing inside a cursor loop is not supported
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+ERROR:  cannot abort transaction inside a cursor loop
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot roll back while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+ERROR:  duplicate key value violates unique constraint "test3_y_key"
+DETAIL:  Key (y)=(1) already exists.
+CONTEXT:  PL/pgSQL function inline_code_block line 9 at COMMIT
+SELECT * FROM test3;
+ y 
+---
+ 1
+(1 row)
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index fa4d573e50..af615deb7e 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -215,6 +215,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1650,6 +1654,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4332,6 +4344,57 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	/*
+	 * XXX This could be implemented by converting the pinned portals to
+	 * holdable ones and organizing the cleanup separately.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("committing inside a cursor loop is not supported")));
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	/*
+	 * Unlike the COMMIT case above, this might not make sense at all,
+	 * especially if the query driving the cursor loop has side effects.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot abort transaction inside a cursor loop")));
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6830,8 +6893,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 */
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
-		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index be779b6fc4..c8667b054a 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1239,6 +1269,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index e802440b45..7589e2df0f 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -198,6 +198,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -260,6 +261,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -325,6 +327,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -897,6 +900,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2151,6 +2158,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2387,6 +2419,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2438,6 +2471,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 1ebb7a7b5e..2b0568a2f4 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -219,15 +219,20 @@ PG_FUNCTION_INFO_V1(plpgsql_call_handler);
 Datum
 plpgsql_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	PLpgSQL_function *func;
 	PLpgSQL_execstate *save_cur_estate;
 	Datum		retval;
 	int			rc;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Find or compile the function */
@@ -255,7 +260,9 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -301,7 +308,7 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Compile the anonymous code block */
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index 553be8c93c..a172031db2 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 39bd82acd1..59a5f40dd8 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
new file mode 100644
index 0000000000..02ee735079
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
@@ -0,0 +1,215 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM test1;
+
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+COMMIT;
+
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+COMMIT;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test4();
+
+
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+
+CALL transaction_test5();
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+
+SELECT * FROM test3;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..39b994f446 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -48,6 +48,7 @@ select module_contents();
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,11 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
  subtransaction
  warning
-(18 rows)
+(20 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..a94e136715
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,144 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+SELECT transaction_test4();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test4", line 2, in <module>
+    plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+PL/Python function "transaction_test4"
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+WARNING:  forcibly aborting a subtransaction that has not been exited
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/Python anonymous code block
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+ERROR:  ValueError: iterating a cursor in an aborted subtransaction
+CONTEXT:  Traceback (most recent call last):
+  PL/Python anonymous code block, line 2, in <module>
+    for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+(1 row)
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+ERROR:  ValueError: iterating a cursor in an aborted subtransaction
+CONTEXT:  Traceback (most recent call last):
+  PL/Python anonymous code block, line 2, in <module>
+    for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 695de30583..527ba67fe1 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -219,14 +219,19 @@ plpython2_validator(PG_FUNCTION_ARGS)
 Datum
 plpython_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	Datum		retval;
 	PLyExecutionContext *exec_ctx;
 	ErrorContextCallback plerrcontext;
 
 	PLy_initialize();
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	/*
@@ -303,7 +308,7 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	PLy_initialize();
 
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
@@ -435,7 +440,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23f99e20ca..3d8983b3b3 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -15,6 +17,7 @@
 
 #include "plpy_cursorobject.h"
 #include "plpy_elog.h"
+#include "plpy_main.h"
 #include "plpy_planobject.h"
 #include "plpy_resultobject.h"
 #include "plpy_spi.h"
@@ -41,6 +44,8 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +100,12 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +588,31 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..0cf74fed54
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,117 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+
+SELECT transaction_test4();
+
+
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+
+
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+
+SELECT * FROM test1;
+
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..007204b99a
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,100 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+CALL transaction_test4a();
+ERROR:  cannot commit while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+CALL transaction_test4b();
+ERROR:  cannot roll back while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 8069784151..770b7da462 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -312,6 +312,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +528,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -797,6 +805,7 @@ static Datum
 pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 				   bool pltrusted)
 {
+	bool		nonatomic;
 	pltcl_proc_desc *prodesc;
 	Tcl_Interp *volatile interp;
 	Tcl_Obj    *tcl_cmd;
@@ -804,8 +813,12 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	int			tcl_rc;
 	Datum		retval;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Connect to SPI manager */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	/* Find or compile the function */
@@ -2936,6 +2949,38 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	SPI_commit();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	SPI_rollback();
+	SPI_start_transaction();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..c752faf665
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,98 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+
+CALL transaction_test4a();
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+
+CALL transaction_test4b();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;

base-commit: 8526bcb2df76d5171b4f4d6dc7a97560a73a5eff
-- 
2.15.1

From 86db8254bcd93585f1036b755a54ae1608ed092f Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Fri, 5 Jan 2018 16:27:53 -0500
Subject: [PATCH v6] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.

- SPI

Add a new function SPI_connect_ext() that is like SPI_connect() but
allows passing option flags.  The only option flag right now is
SPI_OPT_NONATOMIC.  A nonatomic SPI connection can execute transaction
control commands, otherwise it's not allowed.  This is meant to be
passed down from CALL and DO statements which themselves know in which
context they are called.  A nonatomic SPI connection uses different
memory management.  A normal SPI connection allocates its memory in
TopTransactionContext.  For nonatomic connections we use PortalContext
instead.  As the comment in SPI_connect_ext() (previously SPI_connect())
indicates, one could potentially use PortalContext in all cases, but it
seems safest to leave the existing uses alone, because this stuff is
complicated enough already.

SPI also gets new functions SPI_start_transaction(), SPI_commit(), and
SPI_rollback(), which can be used by PLs to implement their transaction
control logic.

- portalmem.c

Some adjustments were made in the code that cleans up portals at
transaction abort.  The portal code could already handle a command
*committing* a transaction and continuing (e.g., VACUUM), but it was not
quite prepared for a command *aborting* a transaction and continuing.

In AtAbort_Portals(), remove the code that marks an active portal as
failed.  As the comment there already predicted, this doesn't work if
the running command wants to keep running after transaction abort.  And
it's actually not necessary, because pquery.c is careful to run all
portal code in a PG_TRY block and explicitly runs MarkPortalFailed() if
there is an exception.  So the code in AtAbort_Portals() is never used
anyway.

In AtAbort_Portals() and AtCleanup_Portals(), we need to be careful not
to clean up active portals too much.  This mirrors similar code in
PreCommit_Portals().

- PL/Perl

Gets new functions spi_commit() and spi_rollback()

- PL/pgSQL

Gets new commands COMMIT and ROLLBACK.

Update the PL/SQL porting example in the documentation to reflect that
transactions are now possible in procedures.

- PL/Python

Gets new functions plpy.commit and plpy.rollback.

- PL/Tcl

Gets new commands commit and rollback.
---
 doc/src/sgml/plperl.sgml                           |  49 +++++
 doc/src/sgml/plpgsql.sgml                          |  91 ++++----
 doc/src/sgml/plpython.sgml                         |  39 ++++
 doc/src/sgml/pltcl.sgml                            |  41 ++++
 doc/src/sgml/ref/call.sgml                         |   7 +
 doc/src/sgml/ref/create_procedure.sgml             |   7 +
 doc/src/sgml/ref/do.sgml                           |   7 +
 doc/src/sgml/spi.sgml                              | 177 +++++++++++++++
 src/backend/commands/functioncmds.c                |  45 +++-
 src/backend/executor/spi.c                         |  99 ++++++++-
 src/backend/tcop/utility.c                         |   6 +-
 src/backend/utils/mmgr/portalmem.c                 |  49 +++--
 src/include/commands/defrem.h                      |   4 +-
 src/include/executor/spi.h                         |   7 +
 src/include/executor/spi_priv.h                    |   4 +
 src/include/nodes/nodes.h                          |   3 +-
 src/include/nodes/parsenodes.h                     |   7 +
 src/include/utils/portal.h                         |   1 +
 src/pl/plperl/GNUmakefile                          |   2 +-
 src/pl/plperl/SPI.xs                               |  10 +
 src/pl/plperl/expected/plperl_transaction.out      | 132 +++++++++++
 src/pl/plperl/plperl.c                             |  59 ++++-
 src/pl/plperl/plperl.h                             |   2 +
 src/pl/plperl/sql/plperl_transaction.sql           | 122 +++++++++++
 src/pl/plpgsql/src/Makefile                        |   2 +-
 .../plpgsql/src/expected/plpgsql_transaction.out   | 241 +++++++++++++++++++++
 src/pl/plpgsql/src/pl_exec.c                       |  66 +++++-
 src/pl/plpgsql/src/pl_funcs.c                      |  44 ++++
 src/pl/plpgsql/src/pl_gram.y                       |  34 +++
 src/pl/plpgsql/src/pl_handler.c                    |  11 +-
 src/pl/plpgsql/src/pl_scanner.c                    |   2 +
 src/pl/plpgsql/src/plpgsql.h                       |  22 +-
 src/pl/plpgsql/src/sql/plpgsql_transaction.sql     | 215 ++++++++++++++++++
 src/pl/plpython/Makefile                           |   1 +
 src/pl/plpython/expected/plpython_test.out         |   4 +-
 src/pl/plpython/expected/plpython_transaction.out  | 144 ++++++++++++
 src/pl/plpython/plpy_main.c                        |  11 +-
 src/pl/plpython/plpy_plpymodule.c                  |  39 ++++
 src/pl/plpython/sql/plpython_transaction.sql       | 117 ++++++++++
 src/pl/tcl/Makefile                                |   2 +-
 src/pl/tcl/expected/pltcl_transaction.out          | 100 +++++++++
 src/pl/tcl/pltcl.c                                 |  95 +++++++-
 src/pl/tcl/sql/pltcl_transaction.sql               |  98 +++++++++
 43 files changed, 2126 insertions(+), 92 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpgsql/src/expected/plpgsql_transaction.out
 create mode 100644 src/pl/plpgsql/src/sql/plpgsql_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 100162dead..9acd41310f 100644
--- a/doc/src/sgml/plperl.sgml
+++ b/doc/src/sgml/plperl.sgml
@@ -661,6 +661,55 @@ <title>Database Access from PL/Perl</title>
     </para>
     </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term>
+      <literal><function>spi_commit()</function></literal>
+      <indexterm>
+       <primary>spi_commit</primary>
+       <secondary>in PL/Perl</secondary>
+     </indexterm>
+     </term>
+     <term>
+      <literal><function>spi_rollback()</function></literal>
+      <indexterm>
+       <primary>spi_rollback</primary>
+       <secondary>in PL/Perl</secondary>
+      </indexterm>
+     </term>
+     <listitem>
+      <para>
+       Commit or roll back the current transaction.  This can only be called
+       in a procedure or anonymous code block (<command>DO</command> command)
+       called from the top level.  (Note that it is not possible to run the
+       SQL commands <command>COMMIT</command> or <command>ROLLBACK</command>
+       via <function>spi_exec_query</function> or similar.  It has to be done
+       using these functions.)  After a transaction is ended, a new
+       transaction is automatically started, so there is no separate function
+       for that.
+      </para>
+
+      <para>
+       Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
  </sect2>
 
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 7d23ed437e..00441af810 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3449,6 +3449,48 @@ <title>Looping Through a Cursor's Result</title>
 
   </sect1>
 
+  <sect1 id="plpgsql-transactions">
+   <title>Transaction Management</title>
+
+   <para>
+    In procedures invoked by the <command>CALL</command> command from the top
+    level as well as in anonymous code blocks (<command>DO</command> command)
+    called from the top level, it is possible to end transactions using the
+    commands <command>COMMIT</command> and <command>ROLLBACK</command>.  A new
+    transaction is started automatically after a transaction is ended using
+    these commands, so there is no separate <command>START
+    TRANSACTION</command> command.  (Note that <command>BEGIN</command> and
+    <command>END</command> have different meanings in PL/pgSQL.)
+   </para>
+
+   <para>
+    Here is a simple example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+</programlisting>
+   </para>
+
+   <para>
+    Transactions cannot be ended inside loops through query results or inside
+    blocks with exception handlers.
+   </para>
+  </sect1>
+
   <sect1 id="plpgsql-errors-and-messages">
    <title>Errors and Messages</title>
 
@@ -5432,14 +5474,13 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 <programlisting>
 CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS
     a_running_job_count INTEGER;
-    PRAGMA AUTONOMOUS_TRANSACTION; -- <co id="co.plpgsql-porting-pragma"/>
 BEGIN
-    LOCK TABLE cs_jobs IN EXCLUSIVE MODE; -- <co id="co.plpgsql-porting-locktable"/>
+    LOCK TABLE cs_jobs IN EXCLUSIVE MODE;
 
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
-        COMMIT; -- free lock <co id="co.plpgsql-porting-commit"/>
+        COMMIT; -- free lock
         raise_application_error(-20000,
                  'Unable to create a new job: a job is currently running.');
     END IF;
@@ -5459,45 +5500,11 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 </programlisting>
    </para>
 
-   <para>
-    Procedures like this can easily be converted into <productname>PostgreSQL</productname>
-    functions returning <type>void</type>. This procedure in
-    particular is interesting because it can teach us some things:
-
-    <calloutlist>
-     <callout arearefs="co.plpgsql-porting-pragma">
-      <para>
-       There is no <literal>PRAGMA</literal> statement in <productname>PostgreSQL</productname>.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-locktable">
-      <para>
-       If you do a <command>LOCK TABLE</command> in <application>PL/pgSQL</application>,
-       the lock will not be released until the calling transaction is
-       finished.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-commit">
-      <para>
-       You cannot issue <command>COMMIT</command> in a
-       <application>PL/pgSQL</application> function.  The function is
-       running within some outer transaction and so <command>COMMIT</command>
-       would imply terminating the function's execution.  However, in
-       this particular case it is not necessary anyway, because the lock
-       obtained by the <command>LOCK TABLE</command> will be released when
-       we raise an error.
-      </para>
-     </callout>
-    </calloutlist>
-   </para>
-
    <para>
     This is how we could port this procedure to <application>PL/pgSQL</application>:
 
 <programlisting>
-CREATE OR REPLACE FUNCTION cs_create_job(v_job_id integer) RETURNS void AS $$
+CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id integer) AS $$
 DECLARE
     a_running_job_count integer;
 BEGIN
@@ -5506,6 +5513,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
+        COMMIT; -- free lock
         RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; -- <co id="co.plpgsql-porting-raise"/>
     END IF;
 
@@ -5518,6 +5526,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
         WHEN unique_violation THEN -- <co id="co.plpgsql-porting-exception"/>
             -- don't worry if it already exists
     END;
+    COMMIT;
 END;
 $$ LANGUAGE plpgsql;
 </programlisting>
@@ -5541,12 +5550,6 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
       </para>
      </callout>
     </calloutlist>
-
-    The main functional difference between this procedure and the
-    Oracle equivalent is that the exclusive lock on the <literal>cs_jobs</literal>
-    table will be held until the calling transaction completes.  Also, if
-    the caller later aborts (for example due to an error), the effects of
-    this procedure will be rolled back.
    </para>
    </example>
   </sect2>
diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 0dbeee1fa2..8641038abe 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -1370,6 +1370,45 @@ <title>Older Python Versions</title>
   </sect2>
  </sect1>
 
+ <sect1 id="plpython-transactions">
+  <title>Transaction Management</title>
+
+  <para>
+   In a procedure called from the top level or an anonymous code block
+   (<command>DO</command> command) called from the top level it is possible to
+   control transactions.  To commit the current transaction, call
+   <literal>plpy.commit()</literal>.  To roll back the current transaction,
+   call <literal>plpy.rollback()</literal>.  (Note that it is not possible to
+   run the SQL commands <command>COMMIT</command> or
+   <command>ROLLBACK</command> via <function>plpy.execute</function> or
+   similar.  It has to be done using these functions.)  After a transaction is
+   ended, a new transaction is automatically started, so there is no separate
+   function for that.
+  </para>
+
+  <para>
+   Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+</programlisting>
+  </para>
+
+  <para>
+   Transactions cannot be ended when an explicit subtransaction is active.
+  </para>
+ </sect1>
+
  <sect1 id="plpython-util">
   <title>Utility Functions</title>
   <para>
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml
index 8018783b0a..a834ab8862 100644
--- a/doc/src/sgml/pltcl.sgml
+++ b/doc/src/sgml/pltcl.sgml
@@ -1002,6 +1002,47 @@ <title>Explicit Subtransactions in PL/Tcl</title>
     </para>
    </sect1>
 
+   <sect1 id="pltcl-transactions">
+    <title>Transaction Management</title>
+
+    <para>
+     In a procedure called from the top level or an anonymous code block
+     (<command>DO</command> command) called from the top level it is possible
+     to control transactions.  To commit the current transaction, call the
+     <literal>commit</literal> command.  To roll back the current transaction,
+     call the <literal>rollback</literal> command.  (Note that it is not
+     possible to run the SQL commands <command>COMMIT</command> or
+     <command>ROLLBACK</command> via <function>spi_exec</function> or similar.
+     It has to be done using these functions.)  After a transaction is ended,
+     a new transaction is automatically started, so there is no separate
+     command for that.
+    </para>
+
+    <para>
+     Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i &lt; 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+    </para>
+
+    <para>
+     Transactions cannot be ended when an explicit subtransaction is active.
+    </para>
+   </sect1>
+
    <sect1 id="pltcl-config">
     <title>PL/Tcl Configuration</title>
 
diff --git a/doc/src/sgml/ref/call.sgml b/doc/src/sgml/ref/call.sgml
index 2741d8d15e..03da4518ee 100644
--- a/doc/src/sgml/ref/call.sgml
+++ b/doc/src/sgml/ref/call.sgml
@@ -70,6 +70,13 @@ <title>Notes</title>
   <para>
    To call a function (not a procedure), use <command>SELECT</command> instead.
   </para>
+
+  <para>
+   If <command>CALL</command> is executed in a transaction block, then the
+   called procedure cannot execute transaction control statements.
+   Transaction control statements are only allowed if <command>CALL</command>
+   is executed in its own transaction.
+  </para>
  </refsect1>
 
  <refsect1>
diff --git a/doc/src/sgml/ref/create_procedure.sgml b/doc/src/sgml/ref/create_procedure.sgml
index d712043824..bbf8b03d04 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -228,6 +228,13 @@ <title>Parameters</title>
        procedure exit, unless the current transaction is rolled back.
       </para>
 
+      <para>
+       If a <literal>SET</literal> clause is attached to a procedure, then
+       that procedure cannot execute transaction control statements (for
+       example, <command>COMMIT</command> and <command>ROLLBACK</command>,
+       depending on the language).
+      </para>
+
       <para>
        See <xref linkend="sql-set"/> and
        <xref linkend="runtime-config"/>
diff --git a/doc/src/sgml/ref/do.sgml b/doc/src/sgml/ref/do.sgml
index 061218b135..b9a6f9a6fd 100644
--- a/doc/src/sgml/ref/do.sgml
+++ b/doc/src/sgml/ref/do.sgml
@@ -91,6 +91,13 @@ <title>Notes</title>
    This is the same privilege requirement as for creating a function
    in the language.
   </para>
+
+  <para>
+   If <command>DO</command> is executed in a transaction block, then the
+   procedure code cannot execute transaction control statements.  Transaction
+   control statements are only allowed if <command>DO</command> is executed in
+   its own transaction.
+  </para>
  </refsect1>
 
  <refsect1 id="sql-do-examples">
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 350f0863e9..10448922b1 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -64,6 +64,7 @@ <title>Interface Functions</title>
 
  <refentry id="spi-spi-connect">
   <indexterm><primary>SPI_connect</primary></indexterm>
+  <indexterm><primary>SPI_connect_ext</primary></indexterm>
 
   <refmeta>
    <refentrytitle>SPI_connect</refentrytitle>
@@ -72,12 +73,17 @@ <title>Interface Functions</title>
 
   <refnamediv>
    <refname>SPI_connect</refname>
+   <refname>SPI_connect_ext</refname>
    <refpurpose>connect a procedure to the SPI manager</refpurpose>
  </refnamediv>
 
  <refsynopsisdiv>
 <synopsis>
 int SPI_connect(void)
+</synopsis>
+
+ <synopsis>
+int SPI_connect_ext(int <parameter>options</parameter>)
 </synopsis>
  </refsynopsisdiv>
 
@@ -90,6 +96,31 @@ <title>Description</title>
    function if you want to execute commands through SPI.  Some utility
    SPI functions can be called from unconnected procedures.
   </para>
+
+  <para>
+   <function>SPI_connect_ext</function> does the same but has an argument that
+   allows passing option flags.  Currently, the following option values are
+   available:
+   <variablelist>
+    <varlistentry>
+     <term><symbol>SPI_OPT_NONATOMIC</symbol></term>
+     <listitem>
+      <para>
+       Sets the SPI connection to be <firstterm>nonatomic</firstterm>, which
+       means that transaction control calls <function>SPI_commit</function>,
+       <function>SPI_rollback</function>, and
+       <function>SPI_start_transaction</function> are allowed.  Otherwise,
+       calling these functions will result in an immediate error.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+
+  <para>
+   <literal>SPI_connect()</literal> is equivalent to
+   <literal>SPI_connect_ext(0)</literal>.
+  </para>
  </refsect1>
 
  <refsect1>
@@ -4325,6 +4356,152 @@ <title>Return Value</title>
 
  </sect1>
 
+ <sect1 id="spi-transaction">
+  <title>Transaction Management</title>
+
+  <para>
+   It is not possible to run transaction control commands such
+   as <command>COMMIT</command> and <command>ROLLBACK</command> through SPI
+   functions such as <function>SPI_execute</function>.  There are, however,
+   separate interface functions that allow transaction control through SPI.
+  </para>
+
+  <para>
+   It is not generally safe and sensible to start and end transactions in
+   arbitrary user-defined SQL-callable functions without taking into account
+   the context in which they are called.  For example, a transaction boundary
+   in the middle of a function that is part of a complex SQL expression that
+   is part of some SQL command will probably result in obscure internal errors
+   or crashes.  The interface functions presented here are primarily intended
+   to be used by procedural language implementations to support transaction
+   management in procedures that are invoked by the <command>CALL</command>
+   command, taking the context of the <command>CALL</command> invocation into
+   account.  SPI procedures implemented in C can implement the same logic, but
+   the details of that are beyond the scope of this documentation.
+  </para>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-commit">
+ <indexterm><primary>SPI_commit</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_commit</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_commit</refname>
+  <refpurpose>commit the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_commit(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_commit</function> commits the current transaction.  It is
+   approximately equivalent to running the SQL
+   command <command>COMMIT</command>.  After a transaction is committed, a new
+   transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-rollback">
+ <indexterm><primary>SPI_rollback</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_rollback</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_rollback</refname>
+  <refpurpose>abort the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_rollback(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_rollback</function> rolls back the current transaction.  It
+   is approximately equivalent to running the SQL
+   command <command>ROLLBACK</command>.  After a transaction is rolled back, a
+   new transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-start-transaction">
+ <indexterm><primary>SPI_start_transaction</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_start_transaction</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_start_transaction</refname>
+  <refpurpose>start a new transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_start_transaction(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_start_transaction</function> starts a new transaction.  It
+   can only be called after <function>SPI_commit</function>
+   or <function>SPI_rollback</function>, as there is no transaction active at
+   that point.  Normally, when an SPI procedure is called, there is already a
+   transaction active, so attempting to start another one before closing out
+   the current one will result in an error.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+ </sect1>
+
  <sect1 id="spi-visibility">
   <title>Visibility of Data Changes</title>
 
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 12ab33f418..9a33d33dcb 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2138,7 +2139,7 @@ IsThereFunctionInNamespace(const char *proname, int pronargs,
  *		Execute inline procedural-language code
  */
 void
-ExecuteDoStmt(DoStmt *stmt)
+ExecuteDoStmt(DoStmt *stmt, bool atomic)
 {
 	InlineCodeBlock *codeblock = makeNode(InlineCodeBlock);
 	ListCell   *arg;
@@ -2200,6 +2201,7 @@ ExecuteDoStmt(DoStmt *stmt)
 	codeblock->langOid = HeapTupleGetOid(languageTuple);
 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
 	codeblock->langIsTrusted = languageStruct->lanpltrusted;
+	codeblock->atomic = atomic;
 
 	if (languageStruct->lanpltrusted)
 	{
@@ -2236,9 +2238,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2249,6 +2270,8 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
+	HeapTuple	tp;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2284,8 +2307,24 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
+
+	/*
+	 * If proconfig is set we can't allow transaction commands because of the
+	 * way the GUC stacking works: The transaction boundary would have to pop
+	 * the proconfig setting off the stack.  That restriction could be lifted
+	 * by redesigning the GUC nesting mechanism a bit.
+	 */
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
+	if (!heap_attisnull(tp, Anum_pg_proc_proconfig))
+		callcontext->atomic = true;
+	ReleaseSysCache(tp);
+
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 4d9b51b947..2e0729d675 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -82,6 +82,12 @@ static bool _SPI_checktuples(void);
 
 int
 SPI_connect(void)
+{
+	return SPI_connect_ext(0);
+}
+
+int
+SPI_connect_ext(int options)
 {
 	int			newdepth;
 
@@ -92,7 +98,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,19 +130,25 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = (options & SPI_OPT_NONATOMIC ? false : true);
+	_SPI_current->internal_xact = false;
 
 	/*
 	 * Create memory contexts for this procedure
 	 *
-	 * XXX it would be better to use PortalContext as the parent context, but
-	 * we may not be inside a portal (consider deferred-trigger execution).
-	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
-	 * because we clean up explicitly in AtEOSubXact_SPI().
+	 * In atomic contexts (the normal case), we use TopTransactionContext,
+	 * otherwise PortalContext, so that it lives across transaction
+	 * boundaries.
+	 *
+	 * XXX It could be better to use PortalContext as the parent context in
+	 * all cases, but we may not be inside a portal (consider deferred-trigger
+	 * execution).  Perhaps CurTransactionContext could be an option?  For now
+	 * it doesn't matter because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : _SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -181,12 +193,82 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+void
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+}
+
+void
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/*
+	 * This restriction is required by PLs implemented on top of SPI.  They
+	 * use subtransactions to establish exception blocks that are supposed to
+	 * be rolled back together if there is an error.  Terminating the
+	 * top-level transaction in such a block violates that idea.  A future PL
+	 * implementation might have different ideas about this, in which case
+	 * this restriction would have to be refined or the check possibly be
+	 * moved out of SPI into the PLs.
+	 */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot commit while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
+void
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/* see under SPI_commit() */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot roll back while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,6 +306,9 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
+		if (connection->internal_xact)
+			break;
+
 		found = true;
 
 		/*
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index ec98a612ec..0b8cfd0da4 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -529,7 +529,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_DoStmt:
-			ExecuteDoStmt((DoStmt *) parsetree);
+			ExecuteDoStmt((DoStmt *) parsetree,
+						  (context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -658,7 +659,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree),
+							(context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index c93c37d74a..2489a94d77 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -736,11 +736,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -754,17 +751,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -804,9 +790,10 @@ AtAbort_Portals(void)
 		 * Although we can't delete the portal data structure proper, we can
 		 * release any memory in subsidiary contexts, such as executor state.
 		 * The cleanup hook was the last thing that might have needed data
-		 * there.
+		 * there.  But leave active portals alone.
 		 */
-		MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
+		if (portal->status != PORTAL_ACTIVE)
+			MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
 	}
 }
 
@@ -826,6 +813,13 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+			continue;
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
@@ -1155,3 +1149,22 @@ ThereAreNoReadyPortals(void)
 
 	return true;
 }
+
+bool
+ThereArePinnedPortals(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->portalPinned)
+			return true;
+	}
+
+	return false;
+}
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 1f18cad963..e0021878fb 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -58,8 +58,8 @@ extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
-extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteDoStmt(DoStmt *stmt, bool atomic);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index 43580c5158..e5bdaecc4e 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -65,6 +65,8 @@ typedef struct _SPI_plan *SPIPlanPtr;
 #define SPI_OK_REL_UNREGISTER	16
 #define SPI_OK_TD_REGISTER		17
 
+#define SPI_OPT_NONATOMIC		(1 << 0)
+
 /* These used to be functions, now just no-ops for backwards compatibility */
 #define SPI_push()	((void) 0)
 #define SPI_pop()	((void) 0)
@@ -78,6 +80,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_connect_ext(int options);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +159,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern void SPI_start_transaction(void);
+extern void SPI_commit(void);
+extern void SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 64f8a450eb..263c8f1453 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 2eb3d6d371..74b094a9c3 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -500,7 +500,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in nodes/parsenodes.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b72178efd1..ccc2fda662 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2803,6 +2803,7 @@ typedef struct InlineCodeBlock
 	char	   *source_text;	/* source text of anonymous code block */
 	Oid			langOid;		/* OID of selected language */
 	bool		langIsTrusted;	/* trusted property of the language */
+	bool		atomic;			/* atomic execution context */
 } InlineCodeBlock;
 
 /* ----------------------
@@ -2815,6 +2816,12 @@ typedef struct CallStmt
 	FuncCall   *funccall;
 } CallStmt;
 
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
 /* ----------------------
  *		Alter Object Rename Statement
  * ----------------------
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 3e7820b51c..41ca51dff9 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -237,5 +237,6 @@ extern PlannedStmt *PortalGetPrimaryStmt(Portal portal);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
 extern bool ThereAreNoReadyPortals(void);
+extern bool ThereArePinnedPortals(void);
 
 #endif							/* PORTAL_H */
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..de5d812cbd 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,15 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		plperl_spi_commit();
+
+void
+spi_spi_rollback()
+	CODE:
+		plperl_spi_rollback();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..5ce33d9c7c
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,132 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination at line 5.
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination at line 5. at line 2.
+CONTEXT:  PL/Perl function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination at line 1. at line 2.
+CONTEXT:  PL/Perl function "transaction_test4"
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+(1 row)
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 41fd0ba421..b3f3b43f8d 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -1929,7 +1929,7 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		current_call_data = &this_call_data;
 
-		if (SPI_connect() != SPI_OK_CONNECT)
+		if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
 
 		select_perl_context(desc.lanpltrusted);
@@ -2396,13 +2396,18 @@ plperl_call_perl_event_trigger_func(plperl_proc_desc *desc,
 static Datum
 plperl_func_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	plperl_proc_desc *prodesc;
 	SV		   *perlret;
 	Datum		retval = 0;
 	ReturnSetInfo *rsi;
 	ErrorContextCallback pl_error_context;
 
-	if (SPI_connect() != SPI_OK_CONNECT)
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	prodesc = compile_plperl_function(fcinfo->flinfo->fn_oid, false, false);
@@ -3945,6 +3950,56 @@ plperl_spi_freeplan(char *query)
 	SPI_freeplan(plan);
 }
 
+void
+plperl_spi_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_commit();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
+void
+plperl_spi_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_rollback();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
 /*
  * Implementation of plperl's elog() function
  *
diff --git a/src/pl/plperl/plperl.h b/src/pl/plperl/plperl.h
index 78366aac04..6fe7803088 100644
--- a/src/pl/plperl/plperl.h
+++ b/src/pl/plperl/plperl.h
@@ -125,6 +125,8 @@ HV		   *plperl_spi_exec_prepared(char *, HV *, int, SV **);
 SV		   *plperl_spi_query_prepared(char *, int, SV **);
 void		plperl_spi_freeplan(char *);
 void		plperl_spi_cursor_close(char *);
+void		plperl_spi_commit(void);
+void		plperl_spi_rollback(void);
 char	   *plperl_sv_to_literal(SV *, char *);
 void		plperl_util_elog(int level, SV *msg);
 
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..081e03f238
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,122 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+
+SELECT transaction_test4();
+
+
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 14a4d83584..91e1ada7ad 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -26,7 +26,7 @@ DATA = plpgsql.control plpgsql--1.0.sql plpgsql--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB)
 
-REGRESS = plpgsql_call plpgsql_control
+REGRESS = plpgsql_call plpgsql_control plpgsql_transaction
 
 all: all-lib
 
diff --git a/src/pl/plpgsql/src/expected/plpgsql_transaction.out b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
new file mode 100644
index 0000000000..8ec22c646c
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
@@ -0,0 +1,241 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+COMMIT;
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+COMMIT;
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test2() line 6 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+SQL statement "CALL transaction_test1()"
+PL/pgSQL function transaction_test3() line 3 at SQL statement
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+SQL statement "DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$"
+PL/pgSQL function transaction_test4() line 3 at EXECUTE
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+CALL transaction_test5();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test5() line 3 at COMMIT
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+ERROR:  committing inside a cursor loop is not supported
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+ERROR:  cannot abort transaction inside a cursor loop
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot roll back while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+ERROR:  duplicate key value violates unique constraint "test3_y_key"
+DETAIL:  Key (y)=(1) already exists.
+CONTEXT:  PL/pgSQL function inline_code_block line 9 at COMMIT
+SELECT * FROM test3;
+ y 
+---
+ 1
+(1 row)
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d096f242cd..4478c5332e 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -290,6 +290,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1731,6 +1735,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4264,6 +4276,57 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	/*
+	 * XXX This could be implemented by converting the pinned portals to
+	 * holdable ones and organizing the cleanup separately.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("committing inside a cursor loop is not supported")));
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	/*
+	 * Unlike the COMMIT case above, this might not make sense at all,
+	 * especially if the query driving the cursor loop has side effects.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot abort transaction inside a cursor loop")));
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6767,8 +6830,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 */
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
-		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 80b8448b7f..f0e85fcfcd 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1239,6 +1269,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index d9cab1ad7e..42f6a2e161 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -198,6 +198,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -260,6 +261,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -325,6 +327,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -897,6 +900,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2151,6 +2158,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2387,6 +2419,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2438,6 +2471,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 4c2ba2f734..a6868e552e 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -219,15 +219,20 @@ PG_FUNCTION_INFO_V1(plpgsql_call_handler);
 Datum
 plpgsql_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	PLpgSQL_function *func;
 	PLpgSQL_execstate *save_cur_estate;
 	Datum		retval;
 	int			rc;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Find or compile the function */
@@ -255,7 +260,9 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -301,7 +308,7 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Compile the anonymous code block */
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index ee9aef8bbc..12a3e6b818 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index c571afa34b..a9b9d91de7 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
new file mode 100644
index 0000000000..02ee735079
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
@@ -0,0 +1,215 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM test1;
+
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+COMMIT;
+
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+COMMIT;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test4();
+
+
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+
+CALL transaction_test5();
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+
+SELECT * FROM test3;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..39b994f446 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -48,6 +48,7 @@ select module_contents();
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,11 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
  subtransaction
  warning
-(18 rows)
+(20 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..a94e136715
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,144 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+SELECT transaction_test4();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test4", line 2, in <module>
+    plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+PL/Python function "transaction_test4"
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+WARNING:  forcibly aborting a subtransaction that has not been exited
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/Python anonymous code block
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+ERROR:  ValueError: iterating a cursor in an aborted subtransaction
+CONTEXT:  Traceback (most recent call last):
+  PL/Python anonymous code block, line 2, in <module>
+    for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+(1 row)
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+ERROR:  ValueError: iterating a cursor in an aborted subtransaction
+CONTEXT:  Traceback (most recent call last):
+  PL/Python anonymous code block, line 2, in <module>
+    for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 695de30583..527ba67fe1 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -219,14 +219,19 @@ plpython2_validator(PG_FUNCTION_ARGS)
 Datum
 plpython_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	Datum		retval;
 	PLyExecutionContext *exec_ctx;
 	ErrorContextCallback plerrcontext;
 
 	PLy_initialize();
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	/*
@@ -303,7 +308,7 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	PLy_initialize();
 
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
@@ -435,7 +440,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23f99e20ca..3d8983b3b3 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -15,6 +17,7 @@
 
 #include "plpy_cursorobject.h"
 #include "plpy_elog.h"
+#include "plpy_main.h"
 #include "plpy_planobject.h"
 #include "plpy_resultobject.h"
 #include "plpy_spi.h"
@@ -41,6 +44,8 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +100,12 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +588,31 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..0cf74fed54
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,117 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+
+SELECT transaction_test4();
+
+
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+
+
+-- FIXME
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+
+SELECT * FROM test1;
+
+
+-- FIXME
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..007204b99a
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,100 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+CALL transaction_test4a();
+ERROR:  cannot commit while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+CALL transaction_test4b();
+ERROR:  cannot roll back while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 8069784151..ab059252d5 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -312,6 +312,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +528,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -797,6 +805,7 @@ static Datum
 pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 				   bool pltrusted)
 {
+	bool		nonatomic;
 	pltcl_proc_desc *prodesc;
 	Tcl_Interp *volatile interp;
 	Tcl_Obj    *tcl_cmd;
@@ -804,8 +813,12 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	int			tcl_rc;
 	Datum		retval;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Connect to SPI manager */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	/* Find or compile the function */
@@ -2936,6 +2949,86 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_commit();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_rollback();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..c752faf665
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,98 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+
+CALL transaction_test4a();
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+
+CALL transaction_test4b();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;

base-commit: 84a6f63e32dbefe3dc76cbe628fab6cbfc26141e
-- 
2.15.1

From 84f35266cc63de1d433d8a5e3549a0e28cb4c1fc Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 16 Jan 2018 10:12:44 -0500
Subject: [PATCH v7] Transaction control in PL procedures

In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language.  Add similar underlying functions to SPI.  Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call.  Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.

- SPI

Add a new function SPI_connect_ext() that is like SPI_connect() but
allows passing option flags.  The only option flag right now is
SPI_OPT_NONATOMIC.  A nonatomic SPI connection can execute transaction
control commands, otherwise it's not allowed.  This is meant to be
passed down from CALL and DO statements which themselves know in which
context they are called.  A nonatomic SPI connection uses different
memory management.  A normal SPI connection allocates its memory in
TopTransactionContext.  For nonatomic connections we use PortalContext
instead.  As the comment in SPI_connect_ext() (previously SPI_connect())
indicates, one could potentially use PortalContext in all cases, but it
seems safest to leave the existing uses alone, because this stuff is
complicated enough already.

SPI also gets new functions SPI_start_transaction(), SPI_commit(), and
SPI_rollback(), which can be used by PLs to implement their transaction
control logic.

- portalmem.c

Some adjustments were made in the code that cleans up portals at
transaction abort.  The portal code could already handle a command
*committing* a transaction and continuing (e.g., VACUUM), but it was not
quite prepared for a command *aborting* a transaction and continuing.

In AtAbort_Portals(), remove the code that marks an active portal as
failed.  As the comment there already predicted, this doesn't work if
the running command wants to keep running after transaction abort.  And
it's actually not necessary, because pquery.c is careful to run all
portal code in a PG_TRY block and explicitly runs MarkPortalFailed() if
there is an exception.  So the code in AtAbort_Portals() is never used
anyway.

In AtAbort_Portals() and AtCleanup_Portals(), we need to be careful not
to clean up active portals too much.  This mirrors similar code in
PreCommit_Portals().

- PL/Perl

Gets new functions spi_commit() and spi_rollback()

- PL/pgSQL

Gets new commands COMMIT and ROLLBACK.

Update the PL/SQL porting example in the documentation to reflect that
transactions are now possible in procedures.

- PL/Python

Gets new functions plpy.commit and plpy.rollback.

- PL/Tcl

Gets new commands commit and rollback.
---
 doc/src/sgml/plperl.sgml                           |  49 +++++
 doc/src/sgml/plpgsql.sgml                          |  91 ++++----
 doc/src/sgml/plpython.sgml                         |  39 ++++
 doc/src/sgml/pltcl.sgml                            |  41 ++++
 doc/src/sgml/ref/call.sgml                         |   7 +
 doc/src/sgml/ref/create_procedure.sgml             |   7 +
 doc/src/sgml/ref/do.sgml                           |   7 +
 doc/src/sgml/spi.sgml                              | 177 +++++++++++++++
 src/backend/commands/functioncmds.c                |  45 +++-
 src/backend/executor/spi.c                         |  99 ++++++++-
 src/backend/tcop/utility.c                         |   6 +-
 src/backend/utils/mmgr/portalmem.c                 |  49 +++--
 src/include/commands/defrem.h                      |   4 +-
 src/include/executor/spi.h                         |   7 +
 src/include/executor/spi_priv.h                    |   4 +
 src/include/nodes/nodes.h                          |   3 +-
 src/include/nodes/parsenodes.h                     |   7 +
 src/include/utils/portal.h                         |   1 +
 src/pl/plperl/GNUmakefile                          |   2 +-
 src/pl/plperl/SPI.xs                               |  10 +
 src/pl/plperl/expected/plperl_transaction.out      | 133 ++++++++++++
 src/pl/plperl/plperl.c                             |  69 +++++-
 src/pl/plperl/plperl.h                             |   2 +
 src/pl/plperl/sql/plperl_transaction.sql           | 120 ++++++++++
 src/pl/plpgsql/src/Makefile                        |   2 +-
 .../plpgsql/src/expected/plpgsql_transaction.out   | 241 +++++++++++++++++++++
 src/pl/plpgsql/src/pl_exec.c                       |  66 +++++-
 src/pl/plpgsql/src/pl_funcs.c                      |  44 ++++
 src/pl/plpgsql/src/pl_gram.y                       |  34 +++
 src/pl/plpgsql/src/pl_handler.c                    |  11 +-
 src/pl/plpgsql/src/pl_scanner.c                    |   2 +
 src/pl/plpgsql/src/plpgsql.h                       |  22 +-
 src/pl/plpgsql/src/sql/plpgsql_transaction.sql     | 215 ++++++++++++++++++
 src/pl/plpython/Makefile                           |   1 +
 src/pl/plpython/expected/plpython_test.out         |   4 +-
 src/pl/plpython/expected/plpython_transaction.out  | 135 ++++++++++++
 src/pl/plpython/plpy_main.c                        |  11 +-
 src/pl/plpython/plpy_plpymodule.c                  |  49 +++++
 src/pl/plpython/sql/plpython_transaction.sql       | 115 ++++++++++
 src/pl/tcl/Makefile                                |   2 +-
 src/pl/tcl/expected/pltcl_transaction.out          | 100 +++++++++
 src/pl/tcl/pltcl.c                                 |  95 +++++++-
 src/pl/tcl/sql/pltcl_transaction.sql               |  98 +++++++++
 43 files changed, 2134 insertions(+), 92 deletions(-)
 create mode 100644 src/pl/plperl/expected/plperl_transaction.out
 create mode 100644 src/pl/plperl/sql/plperl_transaction.sql
 create mode 100644 src/pl/plpgsql/src/expected/plpgsql_transaction.out
 create mode 100644 src/pl/plpgsql/src/sql/plpgsql_transaction.sql
 create mode 100644 src/pl/plpython/expected/plpython_transaction.out
 create mode 100644 src/pl/plpython/sql/plpython_transaction.sql
 create mode 100644 src/pl/tcl/expected/pltcl_transaction.out
 create mode 100644 src/pl/tcl/sql/pltcl_transaction.sql

diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 100162dead..9acd41310f 100644
--- a/doc/src/sgml/plperl.sgml
+++ b/doc/src/sgml/plperl.sgml
@@ -661,6 +661,55 @@ <title>Database Access from PL/Perl</title>
     </para>
     </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term>
+      <literal><function>spi_commit()</function></literal>
+      <indexterm>
+       <primary>spi_commit</primary>
+       <secondary>in PL/Perl</secondary>
+     </indexterm>
+     </term>
+     <term>
+      <literal><function>spi_rollback()</function></literal>
+      <indexterm>
+       <primary>spi_rollback</primary>
+       <secondary>in PL/Perl</secondary>
+      </indexterm>
+     </term>
+     <listitem>
+      <para>
+       Commit or roll back the current transaction.  This can only be called
+       in a procedure or anonymous code block (<command>DO</command> command)
+       called from the top level.  (Note that it is not possible to run the
+       SQL commands <command>COMMIT</command> or <command>ROLLBACK</command>
+       via <function>spi_exec_query</function> or similar.  It has to be done
+       using these functions.)  After a transaction is ended, a new
+       transaction is automatically started, so there is no separate function
+       for that.
+      </para>
+
+      <para>
+       Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
    </variablelist>
  </sect2>
 
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index ddd054c6cc..90a3c00dfe 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3449,6 +3449,48 @@ <title>Looping Through a Cursor's Result</title>
 
   </sect1>
 
+  <sect1 id="plpgsql-transactions">
+   <title>Transaction Management</title>
+
+   <para>
+    In procedures invoked by the <command>CALL</command> command from the top
+    level as well as in anonymous code blocks (<command>DO</command> command)
+    called from the top level, it is possible to end transactions using the
+    commands <command>COMMIT</command> and <command>ROLLBACK</command>.  A new
+    transaction is started automatically after a transaction is ended using
+    these commands, so there is no separate <command>START
+    TRANSACTION</command> command.  (Note that <command>BEGIN</command> and
+    <command>END</command> have different meanings in PL/pgSQL.)
+   </para>
+
+   <para>
+    Here is a simple example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+</programlisting>
+   </para>
+
+   <para>
+    A transaction cannot be ended inside a loop over a query result, nor
+    inside a block with exception handlers.
+   </para>
+  </sect1>
+
   <sect1 id="plpgsql-errors-and-messages">
    <title>Errors and Messages</title>
 
@@ -5432,14 +5474,13 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 <programlisting>
 CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS
     a_running_job_count INTEGER;
-    PRAGMA AUTONOMOUS_TRANSACTION; -- <co id="co.plpgsql-porting-pragma"/>
 BEGIN
-    LOCK TABLE cs_jobs IN EXCLUSIVE MODE; -- <co id="co.plpgsql-porting-locktable"/>
+    LOCK TABLE cs_jobs IN EXCLUSIVE MODE;
 
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
-        COMMIT; -- free lock <co id="co.plpgsql-porting-commit"/>
+        COMMIT; -- free lock
         raise_application_error(-20000,
                  'Unable to create a new job: a job is currently running.');
     END IF;
@@ -5459,45 +5500,11 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
 </programlisting>
    </para>
 
-   <para>
-    Procedures like this can easily be converted into <productname>PostgreSQL</productname>
-    functions returning <type>void</type>. This procedure in
-    particular is interesting because it can teach us some things:
-
-    <calloutlist>
-     <callout arearefs="co.plpgsql-porting-pragma">
-      <para>
-       There is no <literal>PRAGMA</literal> statement in <productname>PostgreSQL</productname>.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-locktable">
-      <para>
-       If you do a <command>LOCK TABLE</command> in <application>PL/pgSQL</application>,
-       the lock will not be released until the calling transaction is
-       finished.
-      </para>
-     </callout>
-
-     <callout arearefs="co.plpgsql-porting-commit">
-      <para>
-       You cannot issue <command>COMMIT</command> in a
-       <application>PL/pgSQL</application> function.  The function is
-       running within some outer transaction and so <command>COMMIT</command>
-       would imply terminating the function's execution.  However, in
-       this particular case it is not necessary anyway, because the lock
-       obtained by the <command>LOCK TABLE</command> will be released when
-       we raise an error.
-      </para>
-     </callout>
-    </calloutlist>
-   </para>
-
    <para>
     This is how we could port this procedure to <application>PL/pgSQL</application>:
 
 <programlisting>
-CREATE OR REPLACE FUNCTION cs_create_job(v_job_id integer) RETURNS void AS $$
+CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id integer) AS $$
 DECLARE
     a_running_job_count integer;
 BEGIN
@@ -5506,6 +5513,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
     SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;
 
     IF a_running_job_count &gt; 0 THEN
+        COMMIT; -- free lock
         RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; -- <co id="co.plpgsql-porting-raise"/>
     END IF;
 
@@ -5518,6 +5526,7 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
         WHEN unique_violation THEN -- <co id="co.plpgsql-porting-exception"/>
             -- don't worry if it already exists
     END;
+    COMMIT;
 END;
 $$ LANGUAGE plpgsql;
 </programlisting>
@@ -5541,12 +5550,6 @@ <title>Porting a Procedure from <application>PL/SQL</application> to <applicatio
       </para>
      </callout>
     </calloutlist>
-
-    The main functional difference between this procedure and the
-    Oracle equivalent is that the exclusive lock on the <literal>cs_jobs</literal>
-    table will be held until the calling transaction completes.  Also, if
-    the caller later aborts (for example due to an error), the effects of
-    this procedure will be rolled back.
    </para>
    </example>
   </sect2>
diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 0dbeee1fa2..8641038abe 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -1370,6 +1370,45 @@ <title>Older Python Versions</title>
   </sect2>
  </sect1>
 
+ <sect1 id="plpython-transactions">
+  <title>Transaction Management</title>
+
+  <para>
+   In a procedure called from the top level or an anonymous code block
+   (<command>DO</command> command) called from the top level it is possible to
+   control transactions.  To commit the current transaction, call
+   <literal>plpy.commit()</literal>.  To roll back the current transaction,
+   call <literal>plpy.rollback()</literal>.  (Note that it is not possible to
+   run the SQL commands <command>COMMIT</command> or
+   <command>ROLLBACK</command> via <function>plpy.execute</function> or
+   similar.  It has to be done using these functions.)  After a transaction is
+   ended, a new transaction is automatically started, so there is no separate
+   function for that.
+  </para>
+
+  <para>
+   Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+</programlisting>
+  </para>
+
+  <para>
+   Transactions cannot be ended when an explicit subtransaction is active.
+  </para>
+ </sect1>
+
  <sect1 id="plpython-util">
   <title>Utility Functions</title>
   <para>
diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml
index 8018783b0a..a834ab8862 100644
--- a/doc/src/sgml/pltcl.sgml
+++ b/doc/src/sgml/pltcl.sgml
@@ -1002,6 +1002,47 @@ <title>Explicit Subtransactions in PL/Tcl</title>
     </para>
    </sect1>
 
+   <sect1 id="pltcl-transactions">
+    <title>Transaction Management</title>
+
+    <para>
+     In a procedure called from the top level or an anonymous code block
+     (<command>DO</command> command) called from the top level it is possible
+     to control transactions.  To commit the current transaction, call the
+     <literal>commit</literal> command.  To roll back the current transaction,
+     call the <literal>rollback</literal> command.  (Note that it is not
+     possible to run the SQL commands <command>COMMIT</command> or
+     <command>ROLLBACK</command> via <function>spi_exec</function> or similar.
+     It has to be done using these functions.)  After a transaction is ended,
+     a new transaction is automatically started, so there is no separate
+     command for that.
+    </para>
+
+    <para>
+     Here is an example:
+<programlisting>
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i &lt; 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+</programlisting>
+    </para>
+
+    <para>
+     Transactions cannot be ended when an explicit subtransaction is active.
+    </para>
+   </sect1>
+
    <sect1 id="pltcl-config">
     <title>PL/Tcl Configuration</title>
 
diff --git a/doc/src/sgml/ref/call.sgml b/doc/src/sgml/ref/call.sgml
index 2741d8d15e..03da4518ee 100644
--- a/doc/src/sgml/ref/call.sgml
+++ b/doc/src/sgml/ref/call.sgml
@@ -70,6 +70,13 @@ <title>Notes</title>
   <para>
    To call a function (not a procedure), use <command>SELECT</command> instead.
   </para>
+
+  <para>
+   If <command>CALL</command> is executed in a transaction block, then the
+   called procedure cannot execute transaction control statements.
+   Transaction control statements are only allowed if <command>CALL</command>
+   is executed in its own transaction.
+  </para>
  </refsect1>
 
  <refsect1>
diff --git a/doc/src/sgml/ref/create_procedure.sgml b/doc/src/sgml/ref/create_procedure.sgml
index d712043824..bbf8b03d04 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -228,6 +228,13 @@ <title>Parameters</title>
        procedure exit, unless the current transaction is rolled back.
       </para>
 
+      <para>
+       If a <literal>SET</literal> clause is attached to a procedure, then
+       that procedure cannot execute transaction control statements (for
+       example, <command>COMMIT</command> and <command>ROLLBACK</command>,
+       depending on the language).
+      </para>
+
       <para>
        See <xref linkend="sql-set"/> and
        <xref linkend="runtime-config"/>
diff --git a/doc/src/sgml/ref/do.sgml b/doc/src/sgml/ref/do.sgml
index 061218b135..b9a6f9a6fd 100644
--- a/doc/src/sgml/ref/do.sgml
+++ b/doc/src/sgml/ref/do.sgml
@@ -91,6 +91,13 @@ <title>Notes</title>
    This is the same privilege requirement as for creating a function
    in the language.
   </para>
+
+  <para>
+   If <command>DO</command> is executed in a transaction block, then the
+   procedure code cannot execute transaction control statements.  Transaction
+   control statements are only allowed if <command>DO</command> is executed in
+   its own transaction.
+  </para>
  </refsect1>
 
  <refsect1 id="sql-do-examples">
diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 350f0863e9..10448922b1 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -64,6 +64,7 @@ <title>Interface Functions</title>
 
  <refentry id="spi-spi-connect">
   <indexterm><primary>SPI_connect</primary></indexterm>
+  <indexterm><primary>SPI_connect_ext</primary></indexterm>
 
   <refmeta>
    <refentrytitle>SPI_connect</refentrytitle>
@@ -72,12 +73,17 @@ <title>Interface Functions</title>
 
   <refnamediv>
    <refname>SPI_connect</refname>
+   <refname>SPI_connect_ext</refname>
    <refpurpose>connect a procedure to the SPI manager</refpurpose>
  </refnamediv>
 
  <refsynopsisdiv>
 <synopsis>
 int SPI_connect(void)
+</synopsis>
+
+ <synopsis>
+int SPI_connect_ext(int <parameter>options</parameter>)
 </synopsis>
  </refsynopsisdiv>
 
@@ -90,6 +96,31 @@ <title>Description</title>
    function if you want to execute commands through SPI.  Some utility
    SPI functions can be called from unconnected procedures.
   </para>
+
+  <para>
+   <function>SPI_connect_ext</function> does the same but has an argument that
+   allows passing option flags.  Currently, the following option values are
+   available:
+   <variablelist>
+    <varlistentry>
+     <term><symbol>SPI_OPT_NONATOMIC</symbol></term>
+     <listitem>
+      <para>
+       Sets the SPI connection to be <firstterm>nonatomic</firstterm>, which
+       means that transaction control calls <function>SPI_commit</function>,
+       <function>SPI_rollback</function>, and
+       <function>SPI_start_transaction</function> are allowed.  Otherwise,
+       calling these functions will result in an immediate error.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+
+  <para>
+   <literal>SPI_connect()</literal> is equivalent to
+   <literal>SPI_connect_ext(0)</literal>.
+  </para>
  </refsect1>
 
  <refsect1>
@@ -4325,6 +4356,152 @@ <title>Return Value</title>
 
  </sect1>
 
+ <sect1 id="spi-transaction">
+  <title>Transaction Management</title>
+
+  <para>
+   It is not possible to run transaction control commands such
+   as <command>COMMIT</command> and <command>ROLLBACK</command> through SPI
+   functions such as <function>SPI_execute</function>.  There are, however,
+   separate interface functions that allow transaction control through SPI.
+  </para>
+
+  <para>
+   It is not generally safe and sensible to start and end transactions in
+   arbitrary user-defined SQL-callable functions without taking into account
+   the context in which they are called.  For example, a transaction boundary
+   in the middle of a function that is part of a complex SQL expression that
+   is part of some SQL command will probably result in obscure internal errors
+   or crashes.  The interface functions presented here are primarily intended
+   to be used by procedural language implementations to support transaction
+   management in procedures that are invoked by the <command>CALL</command>
+   command, taking the context of the <command>CALL</command> invocation into
+   account.  SPI procedures implemented in C can implement the same logic, but
+   the details of that are beyond the scope of this documentation.
+  </para>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-commit">
+ <indexterm><primary>SPI_commit</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_commit</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_commit</refname>
+  <refpurpose>commit the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_commit(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_commit</function> commits the current transaction.  It is
+   approximately equivalent to running the SQL
+   command <command>COMMIT</command>.  After a transaction is committed, a new
+   transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-rollback">
+ <indexterm><primary>SPI_rollback</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_rollback</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_rollback</refname>
+  <refpurpose>abort the current transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_rollback(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_rollback</function> rolls back the current transaction.  It
+   is approximately equivalent to running the SQL
+   command <command>ROLLBACK</command>.  After a transaction is rolled back, a
+   new transaction has to be started
+   using <function>SPI_start_transaction</function> before further database
+   actions can be executed.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+<!-- *********************************************** -->
+
+<refentry id="spi-spi-start-transaction">
+ <indexterm><primary>SPI_start_transaction</primary></indexterm>
+
+ <refmeta>
+  <refentrytitle>SPI_start_transaction</refentrytitle>
+  <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+  <refname>SPI_start_transaction</refname>
+  <refpurpose>start a new transaction</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+void SPI_start_transaction(void)
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <function>SPI_start_transaction</function> starts a new transaction.  It
+   can only be called after <function>SPI_commit</function>
+   or <function>SPI_rollback</function>, as there is no transaction active at
+   that point.  Normally, when an SPI procedure is called, there is already a
+   transaction active, so attempting to start another one before closing out
+   the current one will result in an error.
+  </para>
+
+  <para>
+   This function can only be executed if the SPI connection has been set as
+   nonatomic in the call to <function>SPI_connect_ext</function>.
+  </para>
+ </refsect1>
+</refentry>
+
+ </sect1>
+
  <sect1 id="spi-visibility">
   <title>Visibility of Data Changes</title>
 
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 12ab33f418..9a33d33dcb 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -65,6 +65,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/tqual.h"
@@ -2138,7 +2139,7 @@ IsThereFunctionInNamespace(const char *proname, int pronargs,
  *		Execute inline procedural-language code
  */
 void
-ExecuteDoStmt(DoStmt *stmt)
+ExecuteDoStmt(DoStmt *stmt, bool atomic)
 {
 	InlineCodeBlock *codeblock = makeNode(InlineCodeBlock);
 	ListCell   *arg;
@@ -2200,6 +2201,7 @@ ExecuteDoStmt(DoStmt *stmt)
 	codeblock->langOid = HeapTupleGetOid(languageTuple);
 	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
 	codeblock->langIsTrusted = languageStruct->lanpltrusted;
+	codeblock->atomic = atomic;
 
 	if (languageStruct->lanpltrusted)
 	{
@@ -2236,9 +2238,28 @@ ExecuteDoStmt(DoStmt *stmt)
 
 /*
  * Execute CALL statement
+ *
+ * Inside a top-level CALL statement, transaction-terminating commands such as
+ * COMMIT or a PL-specific equivalent are allowed.  The terminology in the SQL
+ * standard is that CALL establishes a non-atomic execution context.  Most
+ * other commands establish an atomic execution context, in which transaction
+ * control actions are not allowed.  If there are nested executions of CALL,
+ * we want to track the execution context recursively, so that the nested
+ * CALLs can also do transaction control.  Note, however, that for example in
+ * CALL -> SELECT -> CALL, the second call cannot do transaction control,
+ * because the SELECT in between establishes an atomic execution context.
+ *
+ * So when ExecuteCallStmt() is called from the top level, we pass in atomic =
+ * false (recall that that means transactions = yes).  We then create a
+ * CallContext node with content atomic = false, which is passed in the
+ * fcinfo->context field to the procedure invocation.  The language
+ * implementation should then take appropriate measures to allow or prevent
+ * transaction commands based on that information, e.g., call
+ * SPI_set_nonatomic().  The language should also pass on the atomic flag to
+ * any recursive invocations to CALL.
  */
 void
-ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
+ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 {
 	List	   *targs;
 	ListCell   *lc;
@@ -2249,6 +2270,8 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 	AclResult   aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
+	CallContext *callcontext;
+	HeapTuple	tp;
 
 	targs = NIL;
 	foreach(lc, stmt->funccall->args)
@@ -2284,8 +2307,24 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt)
 							   FUNC_MAX_ARGS,
 							   FUNC_MAX_ARGS)));
 
+	callcontext = makeNode(CallContext);
+	callcontext->atomic = atomic;
+
+	/*
+	 * If proconfig is set we can't allow transaction commands because of the
+	 * way the GUC stacking works: The transaction boundary would have to pop
+	 * the proconfig setting off the stack.  That restriction could be lifted
+	 * by redesigning the GUC nesting mechanism a bit.
+	 */
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
+	if (!heap_attisnull(tp, Anum_pg_proc_proconfig))
+		callcontext->atomic = true;
+	ReleaseSysCache(tp);
+
 	fmgr_info(fexpr->funcid, &flinfo);
-	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, NULL, NULL);
+	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
 	foreach (lc, fexpr->args)
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 995f67d266..8e6a074244 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -82,6 +82,12 @@ static bool _SPI_checktuples(void);
 
 int
 SPI_connect(void)
+{
+	return SPI_connect_ext(0);
+}
+
+int
+SPI_connect_ext(int options)
 {
 	int			newdepth;
 
@@ -92,7 +98,7 @@ SPI_connect(void)
 			elog(ERROR, "SPI stack corrupted");
 		newdepth = 16;
 		_SPI_stack = (_SPI_connection *)
-			MemoryContextAlloc(TopTransactionContext,
+			MemoryContextAlloc(TopMemoryContext,
 							   newdepth * sizeof(_SPI_connection));
 		_SPI_stack_depth = newdepth;
 	}
@@ -124,19 +130,25 @@ SPI_connect(void)
 	_SPI_current->execCxt = NULL;
 	_SPI_current->connectSubid = GetCurrentSubTransactionId();
 	_SPI_current->queryEnv = NULL;
+	_SPI_current->atomic = (options & SPI_OPT_NONATOMIC ? false : true);
+	_SPI_current->internal_xact = false;
 
 	/*
 	 * Create memory contexts for this procedure
 	 *
-	 * XXX it would be better to use PortalContext as the parent context, but
-	 * we may not be inside a portal (consider deferred-trigger execution).
-	 * Perhaps CurTransactionContext would do?	For now it doesn't matter
-	 * because we clean up explicitly in AtEOSubXact_SPI().
+	 * In atomic contexts (the normal case), we use TopTransactionContext,
+	 * otherwise PortalContext, so that it lives across transaction
+	 * boundaries.
+	 *
+	 * XXX It could be better to use PortalContext as the parent context in
+	 * all cases, but we may not be inside a portal (consider deferred-trigger
+	 * execution).  Perhaps CurTransactionContext could be an option?  For now
+	 * it doesn't matter because we clean up explicitly in AtEOSubXact_SPI().
 	 */
-	_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->procCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : PortalContext,
 												  "SPI Proc",
 												  ALLOCSET_DEFAULT_SIZES);
-	_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
+	_SPI_current->execCxt = AllocSetContextCreate(_SPI_current->atomic ? TopTransactionContext : _SPI_current->procCxt,
 												  "SPI Exec",
 												  ALLOCSET_DEFAULT_SIZES);
 	/* ... and switch to procedure's context */
@@ -181,12 +193,82 @@ SPI_finish(void)
 	return SPI_OK_FINISH;
 }
 
+void
+SPI_start_transaction(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	StartTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+}
+
+void
+SPI_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/*
+	 * This restriction is required by PLs implemented on top of SPI.  They
+	 * use subtransactions to establish exception blocks that are supposed to
+	 * be rolled back together if there is an error.  Terminating the
+	 * top-level transaction in such a block violates that idea.  A future PL
+	 * implementation might have different ideas about this, in which case
+	 * this restriction would have to be refined or the check possibly be
+	 * moved out of SPI into the PLs.
+	 */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot commit while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	if (ActiveSnapshotSet())
+		PopActiveSnapshot();
+	CommitTransactionCommand();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
+void
+SPI_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	if (_SPI_current->atomic)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("invalid transaction termination")));
+
+	/* see under SPI_commit() */
+	if (IsSubTransaction())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot roll back while a subtransaction is active")));
+
+	_SPI_current->internal_xact = true;
+
+	AbortCurrentTransaction();
+	MemoryContextSwitchTo(oldcontext);
+
+	_SPI_current->internal_xact = false;
+}
+
 /*
  * Clean up SPI state at transaction commit or abort.
  */
 void
 AtEOXact_SPI(bool isCommit)
 {
+	if (_SPI_current && _SPI_current->internal_xact)
+		return;
+
 	/*
 	 * Note that memory contexts belonging to SPI stack entries will be freed
 	 * automatically, so we can ignore them here.  We just need to restore our
@@ -224,6 +306,9 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
 		if (connection->connectSubid != mySubid)
 			break;				/* couldn't be any underneath it either */
 
+		if (connection->internal_xact)
+			break;
+
 		found = true;
 
 		/*
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index ec98a612ec..0b8cfd0da4 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -529,7 +529,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_DoStmt:
-			ExecuteDoStmt((DoStmt *) parsetree);
+			ExecuteDoStmt((DoStmt *) parsetree,
+						  (context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -658,7 +659,8 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_CallStmt:
-			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree));
+			ExecuteCallStmt(pstate, castNode(CallStmt, parsetree),
+							(context != PROCESS_UTILITY_TOPLEVEL || IsTransactionBlock()));
 			break;
 
 		case T_ClusterStmt:
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index 84c68ac189..f3f0add1d6 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -742,11 +742,8 @@ PreCommit_Portals(bool isPrepare)
 /*
  * Abort processing for portals.
  *
- * At this point we reset "active" status and run the cleanup hook if
- * present, but we can't release the portal's memory until the cleanup call.
- *
- * The reason we need to reset active is so that we can replace the unnamed
- * portal, else we'll fail to execute ROLLBACK when it arrives.
+ * At this point we run the cleanup hook if present, but we can't release the
+ * portal's memory until the cleanup call.
  */
 void
 AtAbort_Portals(void)
@@ -760,17 +757,6 @@ AtAbort_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
-		/*
-		 * See similar code in AtSubAbort_Portals().  This would fire if code
-		 * orchestrating multiple top-level transactions within a portal, such
-		 * as VACUUM, caught errors and continued under the same portal with a
-		 * fresh transaction.  No part of core PostgreSQL functions that way.
-		 * XXX Such code would wish the portal to remain ACTIVE, as in
-		 * PreCommit_Portals().
-		 */
-		if (portal->status == PORTAL_ACTIVE)
-			MarkPortalFailed(portal);
-
 		/*
 		 * Do nothing else to cursors held over from a previous transaction.
 		 */
@@ -810,9 +796,10 @@ AtAbort_Portals(void)
 		 * Although we can't delete the portal data structure proper, we can
 		 * release any memory in subsidiary contexts, such as executor state.
 		 * The cleanup hook was the last thing that might have needed data
-		 * there.
+		 * there.  But leave active portals alone.
 		 */
-		MemoryContextDeleteChildren(portal->portalContext);
+		if (portal->status != PORTAL_ACTIVE)
+			MemoryContextDeleteChildren(portal->portalContext);
 	}
 }
 
@@ -832,6 +819,13 @@ AtCleanup_Portals(void)
 	{
 		Portal		portal = hentry->portal;
 
+		/*
+		 * Do not touch active portals --- this can only happen in the case of
+		 * a multi-transaction command.
+		 */
+		if (portal->status == PORTAL_ACTIVE)
+			continue;
+
 		/* Do nothing to cursors held over from a previous transaction */
 		if (portal->createSubid == InvalidSubTransactionId)
 		{
@@ -1161,3 +1155,22 @@ ThereAreNoReadyPortals(void)
 
 	return true;
 }
+
+bool
+ThereArePinnedPortals(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->portalPinned)
+			return true;
+	}
+
+	return false;
+}
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 1f18cad963..e0021878fb 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -58,8 +58,8 @@ extern ObjectAddress CreateTransform(CreateTransformStmt *stmt);
 extern void DropTransformById(Oid transformOid);
 extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
 						   oidvector *proargtypes, Oid nspOid);
-extern void ExecuteDoStmt(DoStmt *stmt);
-extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt);
+extern void ExecuteDoStmt(DoStmt *stmt, bool atomic);
+extern void ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic);
 extern Oid	get_cast_oid(Oid sourcetypeid, Oid targettypeid, bool missing_ok);
 extern Oid	get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
 extern void interpret_function_parameter_list(ParseState *pstate,
diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h
index 43580c5158..e5bdaecc4e 100644
--- a/src/include/executor/spi.h
+++ b/src/include/executor/spi.h
@@ -65,6 +65,8 @@ typedef struct _SPI_plan *SPIPlanPtr;
 #define SPI_OK_REL_UNREGISTER	16
 #define SPI_OK_TD_REGISTER		17
 
+#define SPI_OPT_NONATOMIC		(1 << 0)
+
 /* These used to be functions, now just no-ops for backwards compatibility */
 #define SPI_push()	((void) 0)
 #define SPI_pop()	((void) 0)
@@ -78,6 +80,7 @@ extern PGDLLIMPORT SPITupleTable *SPI_tuptable;
 extern PGDLLIMPORT int SPI_result;
 
 extern int	SPI_connect(void);
+extern int	SPI_connect_ext(int options);
 extern int	SPI_finish(void);
 extern int	SPI_execute(const char *src, bool read_only, long tcount);
 extern int SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
@@ -156,6 +159,10 @@ extern int	SPI_register_relation(EphemeralNamedRelation enr);
 extern int	SPI_unregister_relation(const char *name);
 extern int	SPI_register_trigger_data(TriggerData *tdata);
 
+extern void SPI_start_transaction(void);
+extern void SPI_commit(void);
+extern void SPI_rollback(void);
+
 extern void AtEOXact_SPI(bool isCommit);
 extern void AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid);
 
diff --git a/src/include/executor/spi_priv.h b/src/include/executor/spi_priv.h
index 64f8a450eb..263c8f1453 100644
--- a/src/include/executor/spi_priv.h
+++ b/src/include/executor/spi_priv.h
@@ -36,6 +36,10 @@ typedef struct
 	MemoryContext savedcxt;		/* context of SPI_connect's caller */
 	SubTransactionId connectSubid;	/* ID of connecting subtransaction */
 	QueryEnvironment *queryEnv; /* query environment setup for SPI level */
+
+	/* transaction management support */
+	bool		atomic;			/* atomic execution context, does not allow transactions */
+	bool		internal_xact;	/* SPI-managed transaction boundary, skip cleanup */
 } _SPI_connection;
 
 /*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 2eb3d6d371..74b094a9c3 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -500,7 +500,8 @@ typedef enum NodeTag
 	T_FdwRoutine,				/* in foreign/fdwapi.h */
 	T_IndexAmRoutine,			/* in access/amapi.h */
 	T_TsmRoutine,				/* in access/tsmapi.h */
-	T_ForeignKeyCacheInfo		/* in utils/rel.h */
+	T_ForeignKeyCacheInfo,		/* in utils/rel.h */
+	T_CallContext				/* in nodes/parsenodes.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b72178efd1..ccc2fda662 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2803,6 +2803,7 @@ typedef struct InlineCodeBlock
 	char	   *source_text;	/* source text of anonymous code block */
 	Oid			langOid;		/* OID of selected language */
 	bool		langIsTrusted;	/* trusted property of the language */
+	bool		atomic;			/* atomic execution context */
 } InlineCodeBlock;
 
 /* ----------------------
@@ -2815,6 +2816,12 @@ typedef struct CallStmt
 	FuncCall   *funccall;
 } CallStmt;
 
+typedef struct CallContext
+{
+	NodeTag		type;
+	bool		atomic;
+} CallContext;
+
 /* ----------------------
  *		Alter Object Rename Statement
  * ----------------------
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index bc9d52e506..b903cb0fbe 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -231,5 +231,6 @@ extern PlannedStmt *PortalGetPrimaryStmt(Portal portal);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
 extern bool ThereAreNoReadyPortals(void);
+extern bool ThereArePinnedPortals(void);
 
 #endif							/* PORTAL_H */
diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index b829027d05..933abb47c4 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -55,7 +55,7 @@ endif # win32
 SHLIB_LINK = $(perl_embed_ldflags)
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu
-REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call
+REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction
 # if Perl can support two interpreters in one backend,
 # test plperl-and-plperlu cases
 ifneq ($(PERL),)
diff --git a/src/pl/plperl/SPI.xs b/src/pl/plperl/SPI.xs
index d9e6f579d4..de5d812cbd 100644
--- a/src/pl/plperl/SPI.xs
+++ b/src/pl/plperl/SPI.xs
@@ -17,6 +17,7 @@
 #define PG_NEED_PERL_XSUB_H
 #include "plperl.h"
 #include "plperl_helpers.h"
+#include "executor/spi.h"
 
 
 MODULE = PostgreSQL::InServer::SPI PREFIX = spi_
@@ -152,6 +153,15 @@ spi_spi_cursor_close(sv)
 		plperl_spi_cursor_close(cursor);
 		pfree(cursor);
 
+void
+spi_spi_commit()
+	CODE:
+		plperl_spi_commit();
+
+void
+spi_spi_rollback()
+	CODE:
+		plperl_spi_rollback();
 
 BOOT:
     items = 0;  /* avoid 'unused variable' warning */
diff --git a/src/pl/plperl/expected/plperl_transaction.out b/src/pl/plperl/expected/plperl_transaction.out
new file mode 100644
index 0000000000..bd7b7f8660
--- /dev/null
+++ b/src/pl/plperl/expected/plperl_transaction.out
@@ -0,0 +1,133 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination at line 5.
+CONTEXT:  PL/Perl function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination at line 5. at line 2.
+CONTEXT:  PL/Perl function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination at line 1. at line 2.
+CONTEXT:  PL/Perl function "transaction_test4"
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+ERROR:  cannot commit transaction while a cursor is open at line 6.
+CONTEXT:  PL/Perl anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+ERROR:  cannot abort transaction while a cursor is open at line 6.
+CONTEXT:  PL/Perl anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 10feef11cf..77c41b2821 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -1929,7 +1929,7 @@ plperl_inline_handler(PG_FUNCTION_ARGS)
 
 		current_call_data = &this_call_data;
 
-		if (SPI_connect() != SPI_OK_CONNECT)
+		if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 			elog(ERROR, "could not connect to SPI manager");
 
 		select_perl_context(desc.lanpltrusted);
@@ -2396,13 +2396,18 @@ plperl_call_perl_event_trigger_func(plperl_proc_desc *desc,
 static Datum
 plperl_func_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	plperl_proc_desc *prodesc;
 	SV		   *perlret;
 	Datum		retval = 0;
 	ReturnSetInfo *rsi;
 	ErrorContextCallback pl_error_context;
 
-	if (SPI_connect() != SPI_OK_CONNECT)
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	prodesc = compile_plperl_function(fcinfo->flinfo->fn_oid, false, false);
@@ -3953,6 +3958,66 @@ plperl_spi_freeplan(char *query)
 	SPI_freeplan(plan);
 }
 
+void
+plperl_spi_commit(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		if (ThereArePinnedPortals())
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot commit transaction while a cursor is open")));
+
+		SPI_commit();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
+void
+plperl_spi_rollback(void)
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		if (ThereArePinnedPortals())
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+					 errmsg("cannot abort transaction while a cursor is open")));
+
+		SPI_rollback();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Punt the error to Perl */
+		croak_cstr(edata->message);
+	}
+	PG_END_TRY();
+}
+
 /*
  * Implementation of plperl's elog() function
  *
diff --git a/src/pl/plperl/plperl.h b/src/pl/plperl/plperl.h
index 78366aac04..6fe7803088 100644
--- a/src/pl/plperl/plperl.h
+++ b/src/pl/plperl/plperl.h
@@ -125,6 +125,8 @@ HV		   *plperl_spi_exec_prepared(char *, HV *, int, SV **);
 SV		   *plperl_spi_query_prepared(char *, int, SV **);
 void		plperl_spi_freeplan(char *);
 void		plperl_spi_cursor_close(char *);
+void		plperl_spi_commit(void);
+void		plperl_spi_rollback(void);
 char	   *plperl_sv_to_literal(SV *, char *);
 void		plperl_util_elog(int level, SV *msg);
 
diff --git a/src/pl/plperl/sql/plperl_transaction.sql b/src/pl/plperl/sql/plperl_transaction.sql
new file mode 100644
index 0000000000..5c14d4732e
--- /dev/null
+++ b/src/pl/plperl/sql/plperl_transaction.sql
@@ -0,0 +1,120 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plperl
+$$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plperl
+AS $$
+foreach my $i (0..9) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES ($i)");
+    if ($i % 2 == 0) {
+        spi_commit();
+    } else {
+        spi_rollback();
+    }
+}
+return 1;
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query("CALL transaction_test1()");
+return 1;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plperl
+AS $$
+spi_exec_query('DO LANGUAGE plperl $x$ spi_commit(); $x$');
+return 1;
+$$;
+
+SELECT transaction_test4();
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_commit();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plperl $$
+my $sth = spi_query("SELECT * FROM test2 ORDER BY x");
+my $row;
+while (defined($row = spi_fetchrow($sth))) {
+    spi_exec_query("INSERT INTO test1 (a) VALUES (" . $row->{x} . ")");
+    spi_rollback();
+}
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 14a4d83584..91e1ada7ad 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -26,7 +26,7 @@ DATA = plpgsql.control plpgsql--1.0.sql plpgsql--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB)
 
-REGRESS = plpgsql_call plpgsql_control
+REGRESS = plpgsql_call plpgsql_control plpgsql_transaction
 
 all: all-lib
 
diff --git a/src/pl/plpgsql/src/expected/plpgsql_transaction.out b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
new file mode 100644
index 0000000000..8ec22c646c
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_transaction.out
@@ -0,0 +1,241 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+COMMIT;
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+COMMIT;
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test2() line 6 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test1() line 6 at COMMIT
+SQL statement "CALL transaction_test1()"
+PL/pgSQL function transaction_test3() line 3 at SQL statement
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+SELECT transaction_test4();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function inline_code_block line 1 at COMMIT
+SQL statement "DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$"
+PL/pgSQL function transaction_test4() line 3 at EXECUTE
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+CALL transaction_test5();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/pgSQL function transaction_test5() line 3 at COMMIT
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+ERROR:  committing inside a cursor loop is not supported
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+ERROR:  cannot abort transaction inside a cursor loop
+CONTEXT:  PL/pgSQL function inline_code_block line 7 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at COMMIT
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+ERROR:  cannot roll back while a subtransaction is active
+CONTEXT:  PL/pgSQL function inline_code_block line 5 at ROLLBACK
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+ERROR:  duplicate key value violates unique constraint "test3_y_key"
+DETAIL:  Key (y)=(1) already exists.
+CONTEXT:  PL/pgSQL function inline_code_block line 9 at COMMIT
+SELECT * FROM test3;
+ y 
+---
+ 1
+(1 row)
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d096f242cd..4478c5332e 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -290,6 +290,10 @@ static int exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 					 PLpgSQL_stmt_dynexecute *stmt);
 static int exec_stmt_dynfors(PLpgSQL_execstate *estate,
 				  PLpgSQL_stmt_dynfors *stmt);
+static int exec_stmt_commit(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_commit *stmt);
+static int exec_stmt_rollback(PLpgSQL_execstate *estate,
+				PLpgSQL_stmt_rollback *stmt);
 
 static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
 					 PLpgSQL_function *func,
@@ -1731,6 +1735,14 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 			rc = exec_stmt_close(estate, (PLpgSQL_stmt_close *) stmt);
 			break;
 
+		case PLPGSQL_STMT_COMMIT:
+			rc = exec_stmt_commit(estate, (PLpgSQL_stmt_commit *) stmt);
+			break;
+
+		case PLPGSQL_STMT_ROLLBACK:
+			rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
+			break;
+
 		default:
 			estate->err_stmt = save_estmt;
 			elog(ERROR, "unrecognized cmdtype: %d", stmt->cmd_type);
@@ -4264,6 +4276,57 @@ exec_stmt_close(PLpgSQL_execstate *estate, PLpgSQL_stmt_close *stmt)
 	return PLPGSQL_RC_OK;
 }
 
+/*
+ * exec_stmt_commit
+ *
+ * Commit the transaction.
+ */
+static int
+exec_stmt_commit(PLpgSQL_execstate *estate, PLpgSQL_stmt_commit *stmt)
+{
+	/*
+	 * XXX This could be implemented by converting the pinned portals to
+	 * holdable ones and organizing the cleanup separately.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("committing inside a cursor loop is not supported")));
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
+
+/*
+ * exec_stmt_rollback
+ *
+ * Abort the transaction.
+ */
+static int
+exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
+{
+	/*
+	 * Unlike the COMMIT case above, this might not make sense at all,
+	 * especially if the query driving the cursor loop has side effects.
+	 */
+	if (ThereArePinnedPortals())
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				 errmsg("cannot abort transaction inside a cursor loop")));
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	estate->simple_eval_estate = NULL;
+	plpgsql_create_econtext(estate);
+
+	return PLPGSQL_RC_OK;
+}
 
 /* ----------
  * exec_assign_expr			Put an expression's result into a variable.
@@ -6767,8 +6830,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 */
 	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
-		/* Shouldn't be any econtext stack entries left at commit */
-		Assert(simple_econtext_stack == NULL);
+		simple_econtext_stack = NULL;
 
 		if (shared_simple_eval_estate)
 			FreeExecutorState(shared_simple_eval_estate);
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 80b8448b7f..f0e85fcfcd 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -284,6 +284,10 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 			return "CLOSE";
 		case PLPGSQL_STMT_PERFORM:
 			return "PERFORM";
+		case PLPGSQL_STMT_COMMIT:
+			return "COMMIT";
+		case PLPGSQL_STMT_ROLLBACK:
+			return "ROLLBACK";
 	}
 
 	return "unknown";
@@ -363,6 +367,8 @@ static void free_open(PLpgSQL_stmt_open *stmt);
 static void free_fetch(PLpgSQL_stmt_fetch *stmt);
 static void free_close(PLpgSQL_stmt_close *stmt);
 static void free_perform(PLpgSQL_stmt_perform *stmt);
+static void free_commit(PLpgSQL_stmt_commit *stmt);
+static void free_rollback(PLpgSQL_stmt_rollback *stmt);
 static void free_expr(PLpgSQL_expr *expr);
 
 
@@ -443,6 +449,12 @@ free_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			free_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			free_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			free_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -590,6 +602,16 @@ free_perform(PLpgSQL_stmt_perform *stmt)
 	free_expr(stmt->expr);
 }
 
+static void
+free_commit(PLpgSQL_stmt_commit *stmt)
+{
+}
+
+static void
+free_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+}
+
 static void
 free_exit(PLpgSQL_stmt_exit *stmt)
 {
@@ -777,6 +799,8 @@ static void dump_fetch(PLpgSQL_stmt_fetch *stmt);
 static void dump_cursor_direction(PLpgSQL_stmt_fetch *stmt);
 static void dump_close(PLpgSQL_stmt_close *stmt);
 static void dump_perform(PLpgSQL_stmt_perform *stmt);
+static void dump_commit(PLpgSQL_stmt_commit *stmt);
+static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
 static void dump_expr(PLpgSQL_expr *expr);
 
 
@@ -867,6 +891,12 @@ dump_stmt(PLpgSQL_stmt *stmt)
 		case PLPGSQL_STMT_PERFORM:
 			dump_perform((PLpgSQL_stmt_perform *) stmt);
 			break;
+		case PLPGSQL_STMT_COMMIT:
+			dump_commit((PLpgSQL_stmt_commit *) stmt);
+			break;
+		case PLPGSQL_STMT_ROLLBACK:
+			dump_rollback((PLpgSQL_stmt_rollback *) stmt);
+			break;
 		default:
 			elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
 			break;
@@ -1239,6 +1269,20 @@ dump_perform(PLpgSQL_stmt_perform *stmt)
 	printf("\n");
 }
 
+static void
+dump_commit(PLpgSQL_stmt_commit *stmt)
+{
+	dump_ind();
+	printf("COMMIT\n");
+}
+
+static void
+dump_rollback(PLpgSQL_stmt_rollback *stmt)
+{
+	dump_ind();
+	printf("ROLLBACK\n");
+}
+
 static void
 dump_exit(PLpgSQL_stmt_exit *stmt)
 {
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index d9cab1ad7e..42f6a2e161 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -198,6 +198,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %type <stmt>	stmt_return stmt_raise stmt_assert stmt_execsql
 %type <stmt>	stmt_dynexecute stmt_for stmt_perform stmt_getdiag
 %type <stmt>	stmt_open stmt_fetch stmt_move stmt_close stmt_null
+%type <stmt>	stmt_commit stmt_rollback
 %type <stmt>	stmt_case stmt_foreach_a
 
 %type <list>	proc_exceptions
@@ -260,6 +261,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_COLLATE
 %token <keyword>	K_COLUMN
 %token <keyword>	K_COLUMN_NAME
+%token <keyword>	K_COMMIT
 %token <keyword>	K_CONSTANT
 %token <keyword>	K_CONSTRAINT
 %token <keyword>	K_CONSTRAINT_NAME
@@ -325,6 +327,7 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_RETURN
 %token <keyword>	K_RETURNED_SQLSTATE
 %token <keyword>	K_REVERSE
+%token <keyword>	K_ROLLBACK
 %token <keyword>	K_ROW_COUNT
 %token <keyword>	K_ROWTYPE
 %token <keyword>	K_SCHEMA
@@ -897,6 +900,10 @@ proc_stmt		: pl_block ';'
 						{ $$ = $1; }
 				| stmt_null
 						{ $$ = $1; }
+				| stmt_commit
+						{ $$ = $1; }
+				| stmt_rollback
+						{ $$ = $1; }
 				;
 
 stmt_perform	: K_PERFORM expr_until_semi
@@ -2151,6 +2158,31 @@ stmt_null		: K_NULL ';'
 					}
 				;
 
+stmt_commit		: K_COMMIT ';'
+					{
+						PLpgSQL_stmt_commit *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_commit));
+						new->cmd_type = PLPGSQL_STMT_COMMIT;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+stmt_rollback	: K_ROLLBACK ';'
+					{
+						PLpgSQL_stmt_rollback *new;
+
+						new = palloc(sizeof(PLpgSQL_stmt_rollback));
+						new->cmd_type = PLPGSQL_STMT_ROLLBACK;
+						new->lineno = plpgsql_location_to_lineno(@1);
+
+						$$ = (PLpgSQL_stmt *)new;
+					}
+				;
+
+
 cursor_variable	: T_DATUM
 					{
 						/*
@@ -2387,6 +2419,7 @@ unreserved_keyword	:
 				| K_COLLATE
 				| K_COLUMN
 				| K_COLUMN_NAME
+				| K_COMMIT
 				| K_CONSTANT
 				| K_CONSTRAINT
 				| K_CONSTRAINT_NAME
@@ -2438,6 +2471,7 @@ unreserved_keyword	:
 				| K_RETURN
 				| K_RETURNED_SQLSTATE
 				| K_REVERSE
+				| K_ROLLBACK
 				| K_ROW_COUNT
 				| K_ROWTYPE
 				| K_SCHEMA
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 4c2ba2f734..a6868e552e 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -219,15 +219,20 @@ PG_FUNCTION_INFO_V1(plpgsql_call_handler);
 Datum
 plpgsql_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	PLpgSQL_function *func;
 	PLpgSQL_execstate *save_cur_estate;
 	Datum		retval;
 	int			rc;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Find or compile the function */
@@ -255,7 +260,9 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 			retval = (Datum) 0;
 		}
 		else
+		{
 			retval = plpgsql_exec_function(func, fcinfo, NULL);
+		}
 	}
 	PG_CATCH();
 	{
@@ -301,7 +308,7 @@ plpgsql_inline_handler(PG_FUNCTION_ARGS)
 	/*
 	 * Connect to SPI manager
 	 */
-	if ((rc = SPI_connect()) != SPI_OK_CONNECT)
+	if ((rc = SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC)) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed: %s", SPI_result_code_string(rc));
 
 	/* Compile the anonymous code block */
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index ee9aef8bbc..12a3e6b818 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -106,6 +106,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("collate", K_COLLATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column", K_COLUMN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("column_name", K_COLUMN_NAME, UNRESERVED_KEYWORD)
+	PG_KEYWORD("commit", K_COMMIT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constant", K_CONSTANT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint", K_CONSTRAINT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("constraint_name", K_CONSTRAINT_NAME, UNRESERVED_KEYWORD)
@@ -158,6 +159,7 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("return", K_RETURN, UNRESERVED_KEYWORD)
 	PG_KEYWORD("returned_sqlstate", K_RETURNED_SQLSTATE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("reverse", K_REVERSE, UNRESERVED_KEYWORD)
+	PG_KEYWORD("rollback", K_ROLLBACK, UNRESERVED_KEYWORD)
 	PG_KEYWORD("row_count", K_ROW_COUNT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("rowtype", K_ROWTYPE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("schema", K_SCHEMA, UNRESERVED_KEYWORD)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index c571afa34b..a9b9d91de7 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -105,7 +105,9 @@ typedef enum PLpgSQL_stmt_type
 	PLPGSQL_STMT_OPEN,
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
-	PLPGSQL_STMT_PERFORM
+	PLPGSQL_STMT_PERFORM,
+	PLPGSQL_STMT_COMMIT,
+	PLPGSQL_STMT_ROLLBACK
 } PLpgSQL_stmt_type;
 
 /*
@@ -433,6 +435,24 @@ typedef struct PLpgSQL_stmt_perform
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
 
+/*
+ * COMMIT statement
+ */
+typedef struct PLpgSQL_stmt_commit
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_commit;
+
+/*
+ * ROLLBACK statement
+ */
+typedef struct PLpgSQL_stmt_rollback
+{
+	PLpgSQL_stmt_type cmd_type;
+	int			lineno;
+} PLpgSQL_stmt_rollback;
+
 /*
  * GET DIAGNOSTICS item
  */
diff --git a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
new file mode 100644
index 0000000000..02ee735079
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql
@@ -0,0 +1,215 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpgsql
+$$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+END
+$$;
+
+SELECT * FROM test1;
+
+
+-- transaction commands not allowed when called in transaction block
+START TRANSACTION;
+CALL transaction_test1();
+COMMIT;
+
+START TRANSACTION;
+DO LANGUAGE plpgsql $$ BEGIN COMMIT; END $$;
+COMMIT;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    FOR i IN 0..9 LOOP
+        INSERT INTO test1 (a) VALUES (i);
+        IF i % 2 = 0 THEN
+            COMMIT;
+        ELSE
+            ROLLBACK;
+        END IF;
+    END LOOP;
+    RETURN 1;
+END
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    CALL transaction_test1();
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    EXECUTE 'DO LANGUAGE plpgsql $x$ BEGIN COMMIT; END $x$';
+    RETURN 1;
+END;
+$$;
+
+SELECT transaction_test4();
+
+
+-- proconfig settings currently disallow transaction statements
+CREATE PROCEDURE transaction_test5()
+LANGUAGE plpgsql
+SET work_mem = 555
+AS $$
+BEGIN
+    COMMIT;
+END;
+$$;
+
+CALL transaction_test5();
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        COMMIT;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN SELECT * FROM test2 ORDER BY x LOOP
+        INSERT INTO test1 (a) VALUES (r.x);
+        ROLLBACK;
+    END LOOP;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- commit inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        COMMIT;
+        INSERT INTO test1 (a) VALUES (1/0);
+        COMMIT;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside block with exception handler
+TRUNCATE test1;
+
+DO LANGUAGE plpgsql $$
+BEGIN
+    BEGIN
+        INSERT INTO test1 (a) VALUES (1);
+        ROLLBACK;
+        INSERT INTO test1 (a) VALUES (1/0);
+        ROLLBACK;
+    EXCEPTION
+        WHEN division_by_zero THEN
+            RAISE NOTICE 'caught division_by_zero';
+    END;
+END;
+$$;
+
+SELECT * FROM test1;
+
+
+-- COMMIT failures
+DO LANGUAGE plpgsql $$
+BEGIN
+    CREATE TABLE test3 (y int UNIQUE DEFERRABLE INITIALLY DEFERRED);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (1);
+    INSERT INTO test3 (y) VALUES (2);
+    COMMIT;
+    INSERT INTO test3 (y) VALUES (3);  -- won't get here
+END;
+$$;
+
+SELECT * FROM test3;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
+DROP TABLE test3;
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index cc91afebde..d09910835d 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -90,6 +90,7 @@ REGRESS = \
 	plpython_quote \
 	plpython_composite \
 	plpython_subtransaction \
+	plpython_transaction \
 	plpython_drop
 
 REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 847e4cc412..39b994f446 100644
--- a/src/pl/plpython/expected/plpython_test.out
+++ b/src/pl/plpython/expected/plpython_test.out
@@ -48,6 +48,7 @@ select module_contents();
  Error
  Fatal
  SPIError
+ commit
  cursor
  debug
  error
@@ -60,10 +61,11 @@ select module_contents();
  quote_ident
  quote_literal
  quote_nullable
+ rollback
  spiexceptions
  subtransaction
  warning
-(18 rows)
+(20 rows)
 
 CREATE FUNCTION elog_test_basic() RETURNS void
 AS $$
diff --git a/src/pl/plpython/expected/plpython_transaction.out b/src/pl/plpython/expected/plpython_transaction.out
new file mode 100644
index 0000000000..1fadc69b63
--- /dev/null
+++ b/src/pl/plpython/expected/plpython_transaction.out
@@ -0,0 +1,135 @@
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+CONTEXT:  PL/Python function "transaction_test2"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test3", line 2, in <module>
+    plpy.execute("CALL transaction_test1()")
+PL/Python function "transaction_test3"
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+SELECT transaction_test4();
+ERROR:  spiexceptions.InvalidTransactionTermination: invalid transaction termination
+CONTEXT:  Traceback (most recent call last):
+  PL/Python function "transaction_test4", line 2, in <module>
+    plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+PL/Python function "transaction_test4"
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+WARNING:  forcibly aborting a subtransaction that has not been exited
+ERROR:  cannot commit while a subtransaction is active
+CONTEXT:  PL/Python anonymous code block
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+ERROR:  cannot commit transaction while a cursor is open
+CONTEXT:  PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+ERROR:  cannot abort transaction while a cursor is open
+CONTEXT:  PL/Python anonymous code block
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index 695de30583..527ba67fe1 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -219,14 +219,19 @@ plpython2_validator(PG_FUNCTION_ARGS)
 Datum
 plpython_call_handler(PG_FUNCTION_ARGS)
 {
+	bool		nonatomic;
 	Datum		retval;
 	PLyExecutionContext *exec_ctx;
 	ErrorContextCallback plerrcontext;
 
 	PLy_initialize();
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	/*
@@ -303,7 +308,7 @@ plpython_inline_handler(PG_FUNCTION_ARGS)
 	PLy_initialize();
 
 	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC) != SPI_OK_CONNECT)
 		elog(ERROR, "SPI_connect failed");
 
 	MemSet(&fake_fcinfo, 0, sizeof(fake_fcinfo));
@@ -435,7 +440,7 @@ PLy_push_execution_context(void)
 	PLyExecutionContext *context;
 
 	context = (PLyExecutionContext *)
-		MemoryContextAlloc(TopTransactionContext, sizeof(PLyExecutionContext));
+		MemoryContextAlloc(PortalContext, sizeof(PLyExecutionContext));
 	context->curr_proc = NULL;
 	context->scratch_ctx = NULL;
 	context->next = PLy_execution_contexts;
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 23f99e20ca..11d90e482d 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -6,8 +6,10 @@
 
 #include "postgres.h"
 
+#include "access/xact.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/snapmgr.h"
 
 #include "plpython.h"
 
@@ -15,6 +17,7 @@
 
 #include "plpy_cursorobject.h"
 #include "plpy_elog.h"
+#include "plpy_main.h"
 #include "plpy_planobject.h"
 #include "plpy_resultobject.h"
 #include "plpy_spi.h"
@@ -41,6 +44,8 @@ static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
+static PyObject *PLy_commit(PyObject *self, PyObject *args);
+static PyObject *PLy_rollback(PyObject *self, PyObject *args);
 
 
 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
@@ -95,6 +100,12 @@ static PyMethodDef PLy_methods[] = {
 	 */
 	{"cursor", PLy_cursor, METH_VARARGS, NULL},
 
+	/*
+	 * transaction control
+	 */
+	{"commit", PLy_commit, METH_NOARGS, NULL},
+	{"rollback", PLy_rollback, METH_NOARGS, NULL},
+
 	{NULL, NULL, 0, NULL}
 };
 
@@ -577,3 +588,41 @@ PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
 	 */
 	Py_RETURN_NONE;
 }
+
+static PyObject *
+PLy_commit(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+   if (ThereArePinnedPortals())
+	   ereport(ERROR,
+			   (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("cannot commit transaction while a cursor is open")));
+
+	SPI_commit();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
+
+static PyObject *
+PLy_rollback(PyObject *self, PyObject *args)
+{
+	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
+
+   if (ThereArePinnedPortals())
+	   ereport(ERROR,
+			   (errcode(ERRCODE_INVALID_TRANSACTION_TERMINATION),
+				errmsg("cannot abort transaction while a cursor is open")));
+
+	SPI_rollback();
+	SPI_start_transaction();
+
+	/* was cleared at transaction end, reset pointer */
+	exec_ctx->scratch_ctx = NULL;
+
+	Py_RETURN_NONE;
+}
diff --git a/src/pl/plpython/sql/plpython_transaction.sql b/src/pl/plpython/sql/plpython_transaction.sql
new file mode 100644
index 0000000000..36c7b2ef38
--- /dev/null
+++ b/src/pl/plpython/sql/plpython_transaction.sql
@@ -0,0 +1,115 @@
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+DO
+LANGUAGE plpythonu
+$$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE plpythonu
+AS $$
+for i in range(0, 10):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
+    if i % 2 == 0:
+        plpy.commit()
+    else:
+        plpy.rollback()
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("CALL transaction_test1()")
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- DO block inside function
+CREATE FUNCTION transaction_test4() RETURNS int
+LANGUAGE plpythonu
+AS $$
+plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
+return 1
+$$;
+
+SELECT transaction_test4();
+
+
+-- commit inside subtransaction (prohibited)
+DO LANGUAGE plpythonu $$
+with plpy.subtransaction():
+    plpy.commit()
+$$;
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.commit()
+$$;
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+DO LANGUAGE plpythonu $$
+for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
+    plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
+    plpy.rollback()
+$$;
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 6a92a9b6aa..ef61ee596e 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -28,7 +28,7 @@ DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
        pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
-REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode
+REGRESS = pltcl_setup pltcl_queries pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction
 
 # Tcl on win32 ships with import libraries only for Microsoft Visual C++,
 # which are not compatible with mingw gcc. Therefore we need to build a
diff --git a/src/pl/tcl/expected/pltcl_transaction.out b/src/pl/tcl/expected/pltcl_transaction.out
new file mode 100644
index 0000000000..007204b99a
--- /dev/null
+++ b/src/pl/tcl/expected/pltcl_transaction.out
@@ -0,0 +1,100 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+CREATE TABLE test1 (a int, b text);
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+CALL transaction_test1();
+SELECT * FROM test1;
+ a | b 
+---+---
+ 0 | 
+ 2 | 
+ 4 | 
+ 6 | 
+ 8 | 
+(5 rows)
+
+TRUNCATE test1;
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+SELECT transaction_test2();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+SELECT transaction_test3();
+ERROR:  invalid transaction termination
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+CALL transaction_test4a();
+ERROR:  cannot commit while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+CALL transaction_test4b();
+ERROR:  cannot roll back while a subtransaction is active
+SELECT * FROM test1;
+ a | b 
+---+---
+(0 rows)
+
+DROP TABLE test1;
+DROP TABLE test2;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 8069784151..ab059252d5 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -312,6 +312,10 @@ static int pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
 				  int objc, Tcl_Obj *const objv[]);
 static int pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
+static int pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[]);
 
 static void pltcl_subtrans_begin(MemoryContext oldcontext,
 					 ResourceOwner oldowner);
@@ -524,6 +528,10 @@ pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
 						 pltcl_SPI_lastoid, NULL, NULL);
 	Tcl_CreateObjCommand(interp, "subtransaction",
 						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
 
 	/************************************************************
 	 * Call the appropriate start_proc, if there is one.
@@ -797,6 +805,7 @@ static Datum
 pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 				   bool pltrusted)
 {
+	bool		nonatomic;
 	pltcl_proc_desc *prodesc;
 	Tcl_Interp *volatile interp;
 	Tcl_Obj    *tcl_cmd;
@@ -804,8 +813,12 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 	int			tcl_rc;
 	Datum		retval;
 
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
 	/* Connect to SPI manager */
-	if (SPI_connect() != SPI_OK_CONNECT)
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
 		elog(ERROR, "could not connect to SPI manager");
 
 	/* Find or compile the function */
@@ -2936,6 +2949,86 @@ pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
 }
 
 
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_commit();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_rollback();
+		SPI_start_transaction();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
 /**********************************************************************
  * pltcl_set_tuple_values() - Set variables for all attributes
  *				  of a given tuple
diff --git a/src/pl/tcl/sql/pltcl_transaction.sql b/src/pl/tcl/sql/pltcl_transaction.sql
new file mode 100644
index 0000000000..c752faf665
--- /dev/null
+++ b/src/pl/tcl/sql/pltcl_transaction.sql
@@ -0,0 +1,98 @@
+-- suppress CONTEXT so that function OIDs aren't in output
+\set VERBOSITY terse
+
+CREATE TABLE test1 (a int, b text);
+
+
+CREATE PROCEDURE transaction_test1()
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+$$;
+
+CALL transaction_test1();
+
+SELECT * FROM test1;
+
+
+TRUNCATE test1;
+
+-- not allowed in a function
+CREATE FUNCTION transaction_test2() RETURNS int
+LANGUAGE pltcl
+AS $$
+for {set i 0} {$i < 10} {incr i} {
+    spi_exec "INSERT INTO test1 (a) VALUES ($i)"
+    if {$i % 2 == 0} {
+        commit
+    } else {
+        rollback
+    }
+}
+return 1
+$$;
+
+SELECT transaction_test2();
+
+SELECT * FROM test1;
+
+
+-- also not allowed if procedure is called from a function
+CREATE FUNCTION transaction_test3() RETURNS int
+LANGUAGE pltcl
+AS $$
+spi_exec "CALL transaction_test1()"
+return 1
+$$;
+
+SELECT transaction_test3();
+
+SELECT * FROM test1;
+
+
+-- commit inside cursor loop
+CREATE TABLE test2 (x int);
+INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
+
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4a()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    commit
+}
+$$;
+
+CALL transaction_test4a();
+
+SELECT * FROM test1;
+
+
+-- rollback inside cursor loop
+TRUNCATE test1;
+
+CREATE PROCEDURE transaction_test4b()
+LANGUAGE pltcl
+AS $$
+spi_exec -array row "SELECT * FROM test2 ORDER BY x" {
+    spi_exec "INSERT INTO test1 (a) VALUES ($row(x))"
+    rollback
+}
+$$;
+
+CALL transaction_test4b();
+
+SELECT * FROM test1;
+
+
+DROP TABLE test1;
+DROP TABLE test2;

base-commit: 649aeb123f73e69cf78c52b534c15c51a229d63d
-- 
2.15.1