Replace nested-BEGIN syntax for subtransactions with spec-compliant

SAVEPOINT/RELEASE/ROLLBACK-TO syntax.  (Alvaro)
Cause COMMIT of a failed transaction to report ROLLBACK instead of
COMMIT in its command tag.  (Tom)
Fix a few loose ends in the nested-transactions stuff.

src/backend/executor/spi.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.120 2004/07/01 21:17:13 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.121 2004/07/27 05:10:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1181,18 +1181,16 @@ _SPI_execute(const char *src, int tcount, _SPI_plan *plan)
 					res = SPI_ERROR_CURSOR;
 					goto fail;
 				}
+				else if (IsA(queryTree->utilityStmt, TransactionStmt))
+				{
+					res = SPI_ERROR_TRANSACTION;
+					goto fail;
+				}
 				res = SPI_OK_UTILITY;
 				if (plan == NULL)
 				{
 					ProcessUtility(queryTree->utilityStmt, dest, NULL);
-
-					if (IsA(queryTree->utilityStmt, TransactionStmt))
-					{
-						CommitTransactionCommand();
-						StartTransactionCommand();
-					}
-					else
-						CommandCounterIncrement();
+					CommandCounterIncrement();
 				}
 			}
 			else if (plan == NULL)
@@ -1308,14 +1306,7 @@ _SPI_execute_plan(_SPI_plan *plan, Datum *Values, const char *Nulls,
 			{
 				ProcessUtility(queryTree->utilityStmt, dest, NULL);
 				res = SPI_OK_UTILITY;
-
-				if (IsA(queryTree->utilityStmt, TransactionStmt))
-				{
-					CommitTransactionCommand();
-					StartTransactionCommand();
-				}
-				else
-					CommandCounterIncrement();
+				CommandCounterIncrement();
 			}
 			else
 			{

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.467 2004/07/12 05:37:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.468 2004/07/27 05:10:55 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -386,11 +386,11 @@ static void doNegateFloat(Value *v);
 
 	QUOTE
 
-	READ REAL RECHECK REFERENCES REINDEX RELATIVE_P RENAME REPEATABLE REPLACE
-	RESET RESTART RESTRICT RETURNS REVOKE RIGHT ROLLBACK ROW ROWS
-	RULE
+	READ REAL RECHECK REFERENCES REINDEX RELATIVE_P RELEASE RENAME
+	REPEATABLE REPLACE RESET RESTART RESTRICT RETURNS REVOKE RIGHT
+	ROLLBACK ROW ROWS RULE
 
-	SCHEMA SCROLL SECOND_P SECURITY SELECT SEQUENCE
+	SAVEPOINT SCHEMA SCROLL SECOND_P SECURITY SELECT SEQUENCE
 	SERIALIZABLE SESSION SESSION_USER SET SETOF SHARE
 	SHOW SIMILAR SIMPLE SMALLINT SOME STABLE START STATEMENT
 	STATISTICS STDIN STDOUT STORAGE STRICT_P SUBSTRING SYSID
@@ -3961,6 +3961,30 @@ TransactionStmt:
 					n->options = NIL;
 					$$ = (Node *)n;
 				}
+			| SAVEPOINT ColId
+				{
+					TransactionStmt *n = makeNode(TransactionStmt);
+					n->kind = TRANS_STMT_SAVEPOINT;
+					n->options = list_make1(makeDefElem("savepoint_name",
+														(Node *)makeString($2)));
+					$$ = (Node *)n;
+				}
+			| RELEASE ColId
+				{
+					TransactionStmt *n = makeNode(TransactionStmt);
+					n->kind = TRANS_STMT_RELEASE;
+					n->options = list_make1(makeDefElem("savepoint_name",
+														(Node *)makeString($2)));
+					$$ = (Node *)n;
+				}
+			| ROLLBACK TO ColId
+				{
+					TransactionStmt *n = makeNode(TransactionStmt);
+					n->kind = TRANS_STMT_ROLLBACK_TO;
+					n->options = list_make1(makeDefElem("savepoint_name",
+														(Node *)makeString($3)));
+					$$ = (Node *)n;
+				}
 		;
 
 opt_transaction:	WORK							{}
@@ -7688,6 +7712,7 @@ unreserved_keyword:
 			| RECHECK
 			| REINDEX
 			| RELATIVE_P
+			| RELEASE
 			| RENAME
 			| REPEATABLE
 			| REPLACE
@@ -7699,6 +7724,7 @@ unreserved_keyword:
 			| ROLLBACK
 			| ROWS
 			| RULE
+			| SAVEPOINT
 			| SCHEMA
 			| SCROLL
 			| SECOND_P

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.151 2004/07/12 05:37:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.152 2004/07/27 05:10:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -254,6 +254,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"references", REFERENCES},
 	{"reindex", REINDEX},
 	{"relative", RELATIVE_P},
+	{"release", RELEASE},
 	{"rename", RENAME},
 	{"repeatable", REPEATABLE},
 	{"replace", REPLACE},
@@ -267,6 +268,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"row", ROW},
 	{"rows", ROWS},
 	{"rule", RULE},
+	{"savepoint", SAVEPOINT},
 	{"schema", SCHEMA},
 	{"scroll", SCROLL},
 	{"second", SECOND_P},

src/backend/storage/lmgr/lmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.64 2004/07/01 00:50:59 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.65 2004/07/27 05:10:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -334,21 +334,23 @@ XactLockTableInsert(TransactionId xid)
  *		XactLockTableWait
  *
  * Wait for the specified transaction to commit or abort.
- * We actually wait on the topmost transaction of the transaction tree.
+ *
+ * Note that this does the right thing for subtransactions: if we
+ * wait on a subtransaction, we will be awakened as soon as it aborts
+ * or its parent commits.
  */
 void
 XactLockTableWait(TransactionId xid)
 {
 	LOCKTAG		tag;
 	TransactionId myxid = GetCurrentTransactionId();
-	TransactionId waitXid = SubTransGetTopmostTransaction(xid);
 
-	Assert(!SubTransXidsHaveCommonAncestor(waitXid, myxid));
+	Assert(!SubTransXidsHaveCommonAncestor(xid, myxid));
 
 	MemSet(&tag, 0, sizeof(tag));
 	tag.relId = XactLockTableId;
 	tag.dbId = InvalidOid;
-	tag.objId.xid = waitXid;
+	tag.objId.xid = xid;
 
 	if (!LockAcquire(LockTableId, &tag, myxid,
 					 ShareLock, false))
@@ -358,13 +360,8 @@ XactLockTableWait(TransactionId xid)
 
 	/*
 	 * Transaction was committed/aborted/crashed - we have to update
-	 * pg_clog if transaction is still marked as running.  If it's a
-	 * subtransaction, we can update the parent status too.
+	 * pg_clog if transaction is still marked as running.
 	 */
-	if (!TransactionIdDidCommit(waitXid) && !TransactionIdDidAbort(waitXid))
-	{
-		TransactionIdAbort(waitXid);
-		if (waitXid != xid)
-			TransactionIdAbort(xid);
-	}
+	if (!TransactionIdDidCommit(xid) && !TransactionIdDidAbort(xid))
+		TransactionIdAbort(xid);
 }

src/backend/tcop/postgres.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.424 2004/07/17 03:29:00 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.425 2004/07/27 05:11:03 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -841,8 +841,8 @@ exec_simple_query(const char *query_string)
 				TransactionStmt *stmt = (TransactionStmt *) parsetree;
 
 				if (stmt->kind == TRANS_STMT_COMMIT ||
-					stmt->kind == TRANS_STMT_BEGIN ||
-					stmt->kind == TRANS_STMT_ROLLBACK)
+					stmt->kind == TRANS_STMT_ROLLBACK ||
+					stmt->kind == TRANS_STMT_ROLLBACK_TO)
 					allowit = true;
 			}
 
@@ -1162,8 +1162,8 @@ exec_parse_message(const char *query_string,	/* string to execute */
 				TransactionStmt *stmt = (TransactionStmt *) parsetree;
 
 				if (stmt->kind == TRANS_STMT_COMMIT ||
-					stmt->kind == TRANS_STMT_BEGIN ||
-					stmt->kind == TRANS_STMT_ROLLBACK)
+					stmt->kind == TRANS_STMT_ROLLBACK ||
+					stmt->kind == TRANS_STMT_ROLLBACK_TO)
 					allowit = true;
 			}
 
@@ -1625,8 +1625,8 @@ exec_execute_message(const char *portal_name, long max_rows)
 
 			is_trans_stmt = true;
 			if (stmt->kind == TRANS_STMT_COMMIT ||
-				stmt->kind == TRANS_STMT_BEGIN ||
-				stmt->kind == TRANS_STMT_ROLLBACK)
+				stmt->kind == TRANS_STMT_ROLLBACK ||
+				stmt->kind == TRANS_STMT_ROLLBACK_TO)
 				is_trans_exit = true;
 		}
 	}
@@ -2810,6 +2810,9 @@ PostgresMain(int argc, char *argv[], const char *username)
 		 */
 		MemoryContextSwitchTo(ErrorContext);
 
+		/* Make sure we are using a sane ResourceOwner, too */
+		CurrentResourceOwner = CurTransactionResourceOwner;
+
 		/* Do the recovery */
 		ereport(DEBUG2,
 				(errmsg_internal("AbortCurrentTransaction")));

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.220 2004/06/25 21:55:57 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.221 2004/07/27 05:11:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -354,12 +354,51 @@ ProcessUtility(Node *parsetree,
 						break;
 
 					case TRANS_STMT_COMMIT:
-						EndTransactionBlock();
+						if (!EndTransactionBlock())
+						{
+							/* report unsuccessful commit in completionTag */
+							if (completionTag)
+								strcpy(completionTag, "ROLLBACK");
+						}
 						break;
 
 					case TRANS_STMT_ROLLBACK:
 						UserAbortTransactionBlock();
 						break;
+
+					case TRANS_STMT_SAVEPOINT:
+						{
+							ListCell *cell;
+							char     *name = NULL;
+
+							RequireTransactionChain((void *)stmt, "SAVEPOINT");
+
+							foreach (cell, stmt->options)
+							{
+								DefElem *elem = lfirst(cell);
+								if (strcmp(elem->defname, "savepoint_name") == 0)
+									name = strVal(elem->arg);
+							}
+
+							Assert(PointerIsValid(name));
+
+							DefineSavepoint(name);
+						}
+						break;
+
+					case TRANS_STMT_RELEASE:
+						RequireTransactionChain((void *)stmt, "RELEASE");
+						ReleaseSavepoint(stmt->options);
+						break;
+
+					case TRANS_STMT_ROLLBACK_TO:
+						RequireTransactionChain((void *)stmt, "ROLLBACK TO");
+						RollbackToSavepoint(stmt->options);
+						/*
+						 * CommitTransactionCommand is in charge
+						 * of re-defining the savepoint again
+						 */
+						break;
 				}
 			}
 			break;
@@ -1114,9 +1153,18 @@ CreateCommandTag(Node *parsetree)
 						break;
 
 					case TRANS_STMT_ROLLBACK:
+					case TRANS_STMT_ROLLBACK_TO:
 						tag = "ROLLBACK";
 						break;
 
+					case TRANS_STMT_SAVEPOINT:
+						tag = "SAVEPOINT";
+						break;
+
+					case TRANS_STMT_RELEASE:
+						tag = "RELEASE";
+						break;
+
 					default:
 						tag = "???";
 						break;

src/bin/psql/tab-complete.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.107 2004/05/26 13:56:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.108 2004/07/27 05:11:11 tgl Exp $
  */
 
 /*----------------------------------------------------------------------
@@ -463,8 +463,8 @@ psql_completion(char *text, int start, int end)
 		"ABORT", "ALTER", "ANALYZE", "BEGIN", "CHECKPOINT", "CLOSE", "CLUSTER", "COMMENT",
 		"COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE", "DELETE", "DROP", "EXECUTE",
 		"EXPLAIN", "FETCH", "GRANT", "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY",
-		"PREPARE", "REINDEX", "RESET", "REVOKE", "ROLLBACK", "SELECT", "SET", "SHOW", "START",
-		"TRUNCATE", "UNLISTEN", "UPDATE", "VACUUM", NULL
+		"PREPARE", "REINDEX", "RELEASE", "RESET", "REVOKE", "ROLLBACK", "SAVEPOINT", 
+                "SELECT", "SET", "SHOW", "START", "TRUNCATE", "UNLISTEN", "UPDATE", "VACUUM", NULL
 	};
 
 	static const char * const pgsql_variables[] = {
@@ -722,16 +722,23 @@ psql_completion(char *text, int start, int end)
 	else if (pg_strcasecmp(prev2_wd, "ANALYZE") == 0)
 		COMPLETE_WITH_CONST(";");
 
-/* BEGIN, COMMIT, ROLLBACK, ABORT, */
+/* BEGIN, COMMIT, ABORT */
 	else if (pg_strcasecmp(prev_wd, "BEGIN") == 0 ||
 	         pg_strcasecmp(prev_wd, "END") == 0 ||
 	         pg_strcasecmp(prev_wd, "COMMIT") == 0 ||
-	         pg_strcasecmp(prev_wd, "ROLLBACK") == 0 ||
 	         pg_strcasecmp(prev_wd, "ABORT") == 0)
 	{
 		static const char * const list_TRANS[] =
 		{"WORK", "TRANSACTION", NULL};
 
+		COMPLETE_WITH_LIST(list_TRANS);
+	}
+/* ROLLBACK*/
+	else if ( pg_strcasecmp(prev_wd, "ROLLBACK") == 0 )
+	{
+		static const char * const list_TRANS[] =
+		{"WORK", "TRANSACTION", "TO", NULL};
+
 		COMPLETE_WITH_LIST(list_TRANS);
 	}
 /* CLUSTER */

src/include/access/xact.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/xact.h,v 1.66 2004/07/21 22:31:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/xact.h,v 1.67 2004/07/27 05:11:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,6 +16,7 @@
 
 #include "access/xlog.h"
 #include "storage/relfilenode.h"
+#include "nodes/pg_list.h"
 #include "utils/nabstime.h"
 
 
@@ -101,12 +102,16 @@ extern void StartTransactionCommand(void);
 extern void CommitTransactionCommand(void);
 extern void AbortCurrentTransaction(void);
 extern void BeginTransactionBlock(void);
-extern void EndTransactionBlock(void);
+extern bool EndTransactionBlock(void);
+extern void UserAbortTransactionBlock(void);
+extern void ReleaseSavepoint(List *options);
+extern void DefineSavepoint(char *name);
+extern void RollbackToSavepoint(List *options);
+extern void RollbackAndReleaseSavepoint(List *options);
 extern bool IsSubTransaction(void);
 extern bool IsTransactionBlock(void);
 extern bool IsTransactionOrTransactionBlock(void);
 extern char TransactionBlockStatusCode(void);
-extern void UserAbortTransactionBlock(void);
 extern void AbortOutOfAnyTransaction(void);
 extern void PreventTransactionChain(void *stmtNode, const char *stmtType);
 extern void RequireTransactionChain(void *stmtNode, const char *stmtType);

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.262 2004/07/12 05:38:11 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.263 2004/07/27 05:11:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1514,14 +1514,17 @@ typedef enum TransactionStmtKind
 	TRANS_STMT_BEGIN,
 	TRANS_STMT_START,			/* semantically identical to BEGIN */
 	TRANS_STMT_COMMIT,
-	TRANS_STMT_ROLLBACK
+	TRANS_STMT_ROLLBACK,
+	TRANS_STMT_SAVEPOINT,
+	TRANS_STMT_RELEASE,
+	TRANS_STMT_ROLLBACK_TO
 } TransactionStmtKind;
 
 typedef struct TransactionStmt
 {
 	NodeTag		type;
 	TransactionStmtKind kind;	/* see above */
-	List	   *options;		/* for BEGIN/START only */
+	List	   *options;		/* for BEGIN/START and savepoint commands */
 } TransactionStmt;
 
 /* ----------------------

src/include/utils/errcodes.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.12 2004/06/01 21:49:22 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.13 2004/07/27 05:11:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -213,6 +213,10 @@
 #define ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED	MAKE_SQLSTATE('3','9', 'P','0','1')
 #define ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED	MAKE_SQLSTATE('3','9', 'P','0','2')
 
+/* Class 3B - Savepoint Exception */
+#define ERRCODE_SAVEPOINT_EXCEPTION			MAKE_SQLSTATE('3','B', '0','0','0')
+#define ERRCODE_S_E_INVALID_SPECIFICATION	MAKE_SQLSTATE('3','B', '0','0','1')
+
 /* Class 3D - Invalid Catalog Name */
 #define ERRCODE_INVALID_CATALOG_NAME		MAKE_SQLSTATE('3','D', '0','0','0')
 

src/test/regress/expected/transactions.out

@@ -74,13 +74,14 @@ SET SESSION CHARACTERISTICS AS TRANSACTION READ WRITE;
 CREATE TABLE foobar (a int);
 BEGIN;
 	CREATE TABLE foo (a int);
-	BEGIN;
+	SAVEPOINT one;
 		DROP TABLE foo;
 		CREATE TABLE bar (a int);
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
 		CREATE TABLE baz (a int);
-	COMMIT;
+	RELEASE two;
 	drop TABLE foobar;
 	CREATE TABLE barbaz (a int);
 COMMIT;
@@ -105,18 +106,20 @@ SELECT * FROM baz;		-- should be empty
 -- inserts
 BEGIN;
 	INSERT INTO foo VALUES (1);
-	BEGIN;
+	SAVEPOINT one;
 		INSERT into bar VALUES (1);
 ERROR:  relation "bar" does not exist
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
 		INSERT into barbaz VALUES (1);
-	COMMIT;
-	BEGIN;
-		BEGIN;
+	RELEASE two;
+	SAVEPOINT three;
+		SAVEPOINT four;
 			INSERT INTO foo VALUES (2);
-		COMMIT;
-	ROLLBACK;
+		RELEASE four;
+	ROLLBACK TO three;
+	RELEASE three;
 	INSERT INTO foo VALUES (3);
 COMMIT;
 SELECT * FROM foo;		-- should have 1 and 3
@@ -132,53 +135,168 @@ SELECT * FROM barbaz;	-- should have 1
  1
 (1 row)
 
--- check that starting a subxact in a failed xact or subxact works
+-- test whole-tree commit
 BEGIN;
-	SELECT 0/0;		-- fail the outer xact
-ERROR:  division by zero
-	BEGIN;
-		SELECT 1;	-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
-	COMMIT;
-	SELECT 1;		-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
-	BEGIN;
-		SELECT 1;	-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
-	ROLLBACK;
-	SELECT 1;		-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
+	SAVEPOINT one;
+		SELECT foo;
+ERROR:  column "foo" does not exist
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
+		CREATE TABLE savepoints (a int);
+		SAVEPOINT three;
+			INSERT INTO savepoints VALUES (1);
+			SAVEPOINT four;
+				INSERT INTO savepoints VALUES (2);
+				SAVEPOINT five;
+					INSERT INTO savepoints VALUES (3);
+				ROLLBACK TO five;
 COMMIT;
-SELECT 1;			-- this should work
+COMMIT;		-- should not be in a transaction block
+WARNING:  there is no transaction in progress
+SELECT * FROM savepoints;
+ a 
+---
+ 1
+ 2
+(2 rows)
+
+-- test whole-tree rollback
+BEGIN;
+	SAVEPOINT one;
+		DELETE FROM savepoints WHERE a=1;
+	RELEASE one;
+	SAVEPOINT two;
+		DELETE FROM savepoints WHERE a=1;
+		SAVEPOINT three;
+			DELETE FROM savepoints WHERE a=2;
+ROLLBACK;
+COMMIT;		-- should not be in a transaction block
+WARNING:  there is no transaction in progress
+		
+SELECT * FROM savepoints;
+ a 
+---
+ 1
+ 2
+(2 rows)
+
+-- test whole-tree commit on an aborted subtransaction
+BEGIN;
+	INSERT INTO savepoints VALUES (4);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (5);
+		SELECT foo;
+ERROR:  column "foo" does not exist
+COMMIT;
+SELECT * FROM savepoints;
+ a 
+---
+ 1
+ 2
+(2 rows)
+
+BEGIN;
+	INSERT INTO savepoints VALUES (6);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (7);
+	RELEASE one;
+	INSERT INTO savepoints VALUES (8);
+COMMIT;
+-- rows 6 and 8 should have been created by the same xact
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=6 AND b.a=8;
  ?column? 
 ----------
-        1
+ t
+(1 row)
+
+-- rows 6 and 7 should have been created by different xacts
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=6 AND b.a=7;
+ ?column? 
+----------
+ f
 (1 row)
 
 BEGIN;
-	BEGIN;
-		SELECT 1;	-- this should work
+	INSERT INTO savepoints VALUES (9);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (10);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (11);
+COMMIT;
+SELECT a FROM savepoints WHERE a in (9, 10, 11);
+ a  
+----
+  9
+ 11
+(2 rows)
+
+-- rows 9 and 11 should have been created by different xacts
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=9 AND b.a=11;
  ?column? 
 ----------
-        1
+ f
 (1 row)
 
-		SELECT 0/0;	-- fail the subxact
+BEGIN;
+	INSERT INTO savepoints VALUES (12);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (13);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (14);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (15);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (16);
+			SAVEPOINT three;
+				INSERT INTO savepoints VALUES (17);
+COMMIT;
+SELECT a FROM savepoints WHERE a BETWEEN 12 AND 17;
+ a  
+----
+ 12
+ 15
+ 16
+ 17
+(4 rows)
+
+BEGIN;
+	INSERT INTO savepoints VALUES (18);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (19);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (20);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (21);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (22);
+COMMIT;
+SELECT a FROM savepoints WHERE a BETWEEN 18 AND 22;
+ a  
+----
+ 18
+ 22
+(2 rows)
+
+DROP TABLE savepoints;
+-- only in a transaction block:
+SAVEPOINT one;
+ERROR:  SAVEPOINT may only be used in transaction blocks
+ROLLBACK TO one;
+ERROR:  ROLLBACK TO may only be used in transaction blocks
+RELEASE one;
+ERROR:  RELEASE may only be used in transaction blocks
+-- Only "rollback to" allowed in aborted state
+BEGIN;
+  SAVEPOINT one;
+  SELECT 0/0;
 ERROR:  division by zero
-		SELECT 1;	-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
-		BEGIN;
-			SELECT 1;	-- this should NOT work
-ERROR:  current transaction is aborted, commands ignored until end of transaction block
-		ROLLBACK;
-		BEGIN;
-			SELECT 1;	-- this should NOT work
+  SAVEPOINT two;    -- ignored till the end of ...
 ERROR:  current transaction is aborted, commands ignored until end of transaction block
-		COMMIT;
-		SELECT 1;	-- this should NOT work
+  RELEASE one;      -- ignored till the end of ...
 ERROR:  current transaction is aborted, commands ignored until end of transaction block
-	ROLLBACK;
-	SELECT 1;		-- this should work
+  ROLLBACK TO one;
+  SELECT 1;
  ?column? 
 ----------
         1
@@ -194,7 +312,7 @@ SELECT 1;			-- this should work
 -- check non-transactional behavior of cursors
 BEGIN;
 	DECLARE c CURSOR FOR SELECT unique2 FROM tenk1;
-	BEGIN;
+	SAVEPOINT one;
 		FETCH 10 FROM c;
  unique2 
 ---------
@@ -210,8 +328,7 @@ BEGIN;
        9
 (10 rows)
 
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
 		FETCH 10 FROM c;
  unique2 
 ---------
@@ -227,7 +344,7 @@ BEGIN;
       19
 (10 rows)
 
-	COMMIT;
+	RELEASE one;
 	FETCH 10 FROM c;
  unique2 
 ---------
@@ -245,15 +362,15 @@ BEGIN;
 
 	CLOSE c;
 	DECLARE c CURSOR FOR SELECT unique2/0 FROM tenk1;
-	BEGIN;
+	SAVEPOINT two;
 		FETCH 10 FROM c;
 ERROR:  division by zero
-	ROLLBACK;
+	ROLLBACK TO two;
 	-- c is now dead to the world ...
-	BEGIN;
 		FETCH 10 FROM c;
 ERROR:  portal "c" cannot be run
-	ROLLBACK;
+	ROLLBACK TO two;
+	RELEASE two;
 	FETCH 10 FROM c;
 ERROR:  portal "c" cannot be run
 COMMIT;

src/test/regress/sql/transactions.sql

@@ -61,13 +61,14 @@ SET SESSION CHARACTERISTICS AS TRANSACTION READ WRITE;
 CREATE TABLE foobar (a int);
 BEGIN;
 	CREATE TABLE foo (a int);
-	BEGIN;
+	SAVEPOINT one;
 		DROP TABLE foo;
 		CREATE TABLE bar (a int);
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
 		CREATE TABLE baz (a int);
-	COMMIT;
+	RELEASE two;
 	drop TABLE foobar;
 	CREATE TABLE barbaz (a int);
 COMMIT;
@@ -80,76 +81,156 @@ SELECT * FROM baz;		-- should be empty
 -- inserts
 BEGIN;
 	INSERT INTO foo VALUES (1);
-	BEGIN;
+	SAVEPOINT one;
 		INSERT into bar VALUES (1);
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
 		INSERT into barbaz VALUES (1);
-	COMMIT;
-	BEGIN;
-		BEGIN;
+	RELEASE two;
+	SAVEPOINT three;
+		SAVEPOINT four;
 			INSERT INTO foo VALUES (2);
-		COMMIT;
-	ROLLBACK;
+		RELEASE four;
+	ROLLBACK TO three;
+	RELEASE three;
 	INSERT INTO foo VALUES (3);
 COMMIT;
 SELECT * FROM foo;		-- should have 1 and 3
 SELECT * FROM barbaz;	-- should have 1
 
--- check that starting a subxact in a failed xact or subxact works
+-- test whole-tree commit
 BEGIN;
-	SELECT 0/0;		-- fail the outer xact
-	BEGIN;
-		SELECT 1;	-- this should NOT work
-	COMMIT;
-	SELECT 1;		-- this should NOT work
-	BEGIN;
-		SELECT 1;	-- this should NOT work
-	ROLLBACK;
-	SELECT 1;		-- this should NOT work
+	SAVEPOINT one;
+		SELECT foo;
+	ROLLBACK TO one;
+	RELEASE one;
+	SAVEPOINT two;
+		CREATE TABLE savepoints (a int);
+		SAVEPOINT three;
+			INSERT INTO savepoints VALUES (1);
+			SAVEPOINT four;
+				INSERT INTO savepoints VALUES (2);
+				SAVEPOINT five;
+					INSERT INTO savepoints VALUES (3);
+				ROLLBACK TO five;
 COMMIT;
-SELECT 1;			-- this should work
+COMMIT;		-- should not be in a transaction block
+SELECT * FROM savepoints;
+
+-- test whole-tree rollback
+BEGIN;
+	SAVEPOINT one;
+		DELETE FROM savepoints WHERE a=1;
+	RELEASE one;
+	SAVEPOINT two;
+		DELETE FROM savepoints WHERE a=1;
+		SAVEPOINT three;
+			DELETE FROM savepoints WHERE a=2;
+ROLLBACK;
+COMMIT;		-- should not be in a transaction block
+		
+SELECT * FROM savepoints;
+
+-- test whole-tree commit on an aborted subtransaction
+BEGIN;
+	INSERT INTO savepoints VALUES (4);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (5);
+		SELECT foo;
+COMMIT;
+SELECT * FROM savepoints;
+
+BEGIN;
+	INSERT INTO savepoints VALUES (6);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (7);
+	RELEASE one;
+	INSERT INTO savepoints VALUES (8);
+COMMIT;
+-- rows 6 and 8 should have been created by the same xact
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=6 AND b.a=8;
+-- rows 6 and 7 should have been created by different xacts
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=6 AND b.a=7;
+
+BEGIN;
+	INSERT INTO savepoints VALUES (9);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (10);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (11);
+COMMIT;
+SELECT a FROM savepoints WHERE a in (9, 10, 11);
+-- rows 9 and 11 should have been created by different xacts
+SELECT a.xmin = b.xmin FROM savepoints a, savepoints b WHERE a.a=9 AND b.a=11;
+
+BEGIN;
+	INSERT INTO savepoints VALUES (12);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (13);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (14);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (15);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (16);
+			SAVEPOINT three;
+				INSERT INTO savepoints VALUES (17);
+COMMIT;
+SELECT a FROM savepoints WHERE a BETWEEN 12 AND 17;
+
+BEGIN;
+	INSERT INTO savepoints VALUES (18);
+	SAVEPOINT one;
+		INSERT INTO savepoints VALUES (19);
+		SAVEPOINT two;
+			INSERT INTO savepoints VALUES (20);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (21);
+	ROLLBACK TO one;
+		INSERT INTO savepoints VALUES (22);
+COMMIT;
+SELECT a FROM savepoints WHERE a BETWEEN 18 AND 22;
+
+DROP TABLE savepoints;
 
+-- only in a transaction block:
+SAVEPOINT one;
+ROLLBACK TO one;
+RELEASE one;
+
+-- Only "rollback to" allowed in aborted state
 BEGIN;
-	BEGIN;
-		SELECT 1;	-- this should work
-		SELECT 0/0;	-- fail the subxact
-		SELECT 1;	-- this should NOT work
-		BEGIN;
-			SELECT 1;	-- this should NOT work
-		ROLLBACK;
-		BEGIN;
-			SELECT 1;	-- this should NOT work
-		COMMIT;
-		SELECT 1;	-- this should NOT work
-	ROLLBACK;
-	SELECT 1;		-- this should work
+  SAVEPOINT one;
+  SELECT 0/0;
+  SAVEPOINT two;    -- ignored till the end of ...
+  RELEASE one;      -- ignored till the end of ...
+  ROLLBACK TO one;
+  SELECT 1;
 COMMIT;
 SELECT 1;			-- this should work
 
 -- check non-transactional behavior of cursors
 BEGIN;
 	DECLARE c CURSOR FOR SELECT unique2 FROM tenk1;
-	BEGIN;
+	SAVEPOINT one;
 		FETCH 10 FROM c;
-	ROLLBACK;
-	BEGIN;
+	ROLLBACK TO one;
 		FETCH 10 FROM c;
-	COMMIT;
+	RELEASE one;
 	FETCH 10 FROM c;
 	CLOSE c;
 	DECLARE c CURSOR FOR SELECT unique2/0 FROM tenk1;
-	BEGIN;
+	SAVEPOINT two;
 		FETCH 10 FROM c;
-	ROLLBACK;
+	ROLLBACK TO two;
 	-- c is now dead to the world ...
-	BEGIN;
 		FETCH 10 FROM c;
-	ROLLBACK;
+	ROLLBACK TO two;
+	RELEASE two;
 	FETCH 10 FROM c;
 COMMIT;
 
-
 DROP TABLE foo;
 DROP TABLE baz;
 DROP TABLE barbaz;