From 65bfb7be0aee872eb0405a77ec23ee2483745b37 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Fri, 16 Feb 2018 21:37:55 -0500 Subject: [PATCH v1 7/8] Transaction chaining Add command variants COMMIT AND CHAIN and ROLLBACK AND CHAIN, which start new transactions with the same transaction characteristics as the just finished one, per SQL standard. --- doc/src/sgml/ref/abort.sgml | 14 ++- doc/src/sgml/ref/commit.sgml | 14 ++- doc/src/sgml/ref/end.sgml | 14 ++- doc/src/sgml/ref/rollback.sgml | 14 ++- src/backend/access/transam/xact.c | 74 ++++++++++++++- src/backend/nodes/copyfuncs.c | 1 + src/backend/nodes/equalfuncs.c | 1 + src/backend/parser/gram.y | 19 +++- src/backend/tcop/utility.c | 4 +- src/include/access/xact.h | 4 +- src/include/nodes/parsenodes.h | 1 + src/test/regress/expected/transactions.out | 139 +++++++++++++++++++++++++++++ src/test/regress/sql/transactions.sql | 49 ++++++++++ 13 files changed, 333 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/ref/abort.sgml b/doc/src/sgml/ref/abort.sgml index 21799d2a83..0372913365 100644 --- a/doc/src/sgml/ref/abort.sgml +++ b/doc/src/sgml/ref/abort.sgml @@ -21,7 +21,7 @@ -ABORT [ WORK | TRANSACTION ] +ABORT [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ] @@ -51,6 +51,18 @@ Parameters + + + AND CHAIN + + + If AND CHAIN is specified, a new transaction is + immediately started with the same transaction characteristics (see ) as the just finished one. Otherwise, + no new transaction is started. + + + diff --git a/doc/src/sgml/ref/commit.sgml b/doc/src/sgml/ref/commit.sgml index b2e8d5d180..37c706a66f 100644 --- a/doc/src/sgml/ref/commit.sgml +++ b/doc/src/sgml/ref/commit.sgml @@ -21,7 +21,7 @@ -COMMIT [ WORK | TRANSACTION ] +COMMIT [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ] @@ -48,6 +48,18 @@ Parameters + + + AND CHAIN + + + If AND CHAIN is specified, a new transaction is + immediately started with the same transaction characteristics (see ) as the just finished one. Otherwise, + no new transaction is started. + + + diff --git a/doc/src/sgml/ref/end.sgml b/doc/src/sgml/ref/end.sgml index 7523315f34..8b8f4f0dbb 100644 --- a/doc/src/sgml/ref/end.sgml +++ b/doc/src/sgml/ref/end.sgml @@ -21,7 +21,7 @@ -END [ WORK | TRANSACTION ] +END [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ] @@ -50,6 +50,18 @@ Parameters + + + AND CHAIN + + + If AND CHAIN is specified, a new transaction is + immediately started with the same transaction characteristics (see ) as the just finished one. Otherwise, + no new transaction is started. + + + diff --git a/doc/src/sgml/ref/rollback.sgml b/doc/src/sgml/ref/rollback.sgml index 3cafb848a9..3019273a47 100644 --- a/doc/src/sgml/ref/rollback.sgml +++ b/doc/src/sgml/ref/rollback.sgml @@ -21,7 +21,7 @@ -ROLLBACK [ WORK | TRANSACTION ] +ROLLBACK [ WORK | TRANSACTION ] [ AND [ NO ] CHAIN ] @@ -47,6 +47,18 @@ Parameters + + + AND CHAIN + + + If AND CHAIN is specified, a new transaction is + immediately started with the same transaction characteristics (see ) as the just finished one. Otherwise, + no new transaction is started. + + + diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 15edc93d91..3e468f4d38 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -189,6 +189,7 @@ typedef struct TransactionStateData bool startedInRecovery; /* did we start in recovery? */ bool didLogXid; /* has xid been included in WAL record? */ int parallelModeLevel; /* Enter/ExitParallelMode counter */ + bool chain; /* start a new block after this one */ struct TransactionStateData *parent; /* back link to parent */ } TransactionStateData; @@ -220,6 +221,7 @@ static TransactionStateData TopTransactionStateData = { false, /* startedInRecovery */ false, /* didLogXid */ 0, /* parallelModeLevel */ + false, /* chain */ NULL /* link to parent state block */ }; @@ -2738,6 +2740,36 @@ StartTransactionCommand(void) MemoryContextSwitchTo(CurTransactionContext); } + +/* + * Simple system for saving and restoring transaction characteristics + * (isolation level, read only, deferrable). We need this for transaction + * chaining, so that we can set the characteristics of the new transaction to + * be the same as the previous one. (We need something like this because the + * GUC system resets the characteristics at transaction end, so for example + * just skipping the reset in StartTransaction() won't work.) + */ +static int save_XactIsoLevel; +static bool save_XactReadOnly; +static bool save_XactDeferrable; + +static void +SaveTransactionCharacteristics(void) +{ + save_XactIsoLevel = XactIsoLevel; + save_XactReadOnly = XactReadOnly; + save_XactDeferrable = XactDeferrable; +} + +static void +RestoreTransactionCharacteristics(void) +{ + XactIsoLevel = save_XactIsoLevel; + XactReadOnly = save_XactReadOnly; + XactDeferrable = save_XactDeferrable; +} + + /* * CommitTransactionCommand */ @@ -2746,6 +2778,9 @@ CommitTransactionCommand(void) { TransactionState s = CurrentTransactionState; + if (s->chain) + SaveTransactionCharacteristics(); + switch (s->blockState) { /* @@ -2797,6 +2832,13 @@ CommitTransactionCommand(void) case TBLOCK_END: CommitTransaction(); s->blockState = TBLOCK_DEFAULT; + if (s->chain) + { + StartTransaction(); + s->blockState = TBLOCK_INPROGRESS; + s->chain = false; + RestoreTransactionCharacteristics(); + } break; /* @@ -2816,6 +2858,13 @@ CommitTransactionCommand(void) case TBLOCK_ABORT_END: CleanupTransaction(); s->blockState = TBLOCK_DEFAULT; + if (s->chain) + { + StartTransaction(); + s->blockState = TBLOCK_INPROGRESS; + s->chain = false; + RestoreTransactionCharacteristics(); + } break; /* @@ -2827,6 +2876,13 @@ CommitTransactionCommand(void) AbortTransaction(); CleanupTransaction(); s->blockState = TBLOCK_DEFAULT; + if (s->chain) + { + StartTransaction(); + s->blockState = TBLOCK_INPROGRESS; + s->chain = false; + RestoreTransactionCharacteristics(); + } break; /* @@ -3481,7 +3537,7 @@ PrepareTransactionBlock(const char *gid) bool result; /* Set up to commit the current transaction */ - result = EndTransactionBlock(); + result = EndTransactionBlock(false); /* If successful, change outer tblock state to PREPARE */ if (result) @@ -3527,7 +3583,7 @@ PrepareTransactionBlock(const char *gid) * resource owner, etc while executing inside a Portal. */ bool -EndTransactionBlock(void) +EndTransactionBlock(bool chain) { TransactionState s = CurrentTransactionState; bool result = false; @@ -3653,6 +3709,13 @@ EndTransactionBlock(void) break; } + Assert(s->blockState == TBLOCK_STARTED || + s->blockState == TBLOCK_END || + s->blockState == TBLOCK_ABORT_END || + s->blockState == TBLOCK_ABORT_PENDING); + + s->chain = chain; + return result; } @@ -3663,7 +3726,7 @@ EndTransactionBlock(void) * As above, we don't actually do anything here except change blockState. */ void -UserAbortTransactionBlock(void) +UserAbortTransactionBlock(bool chain) { TransactionState s = CurrentTransactionState; @@ -3761,6 +3824,11 @@ UserAbortTransactionBlock(void) BlockStateAsString(s->blockState)); break; } + + Assert(s->blockState == TBLOCK_ABORT_END || + s->blockState == TBLOCK_ABORT_PENDING); + + s->chain = chain; } /* diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index b013539ee9..7e0a0a90d5 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -3603,6 +3603,7 @@ _copyTransactionStmt(const TransactionStmt *from) COPY_NODE_FIELD(options); COPY_STRING_FIELD(savepoint_name); COPY_STRING_FIELD(gid); + COPY_SCALAR_FIELD(chain); return newnode; } diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index ba5ebdf408..8e22a97818 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -1514,6 +1514,7 @@ _equalTransactionStmt(const TransactionStmt *a, const TransactionStmt *b) COMPARE_NODE_FIELD(options); COMPARE_STRING_FIELD(savepoint_name); COMPARE_STRING_FIELD(gid); + COMPARE_SCALAR_FIELD(chain); return true; } diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index ecb2494226..a5e75c9cbf 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -309,6 +309,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type opt_or_replace opt_grant_grant_option opt_grant_admin_option opt_nowait opt_if_exists opt_with_data + opt_transaction_chain %type opt_nowait_or_skip %type OptRoleList AlterOptRoleList @@ -9826,11 +9827,12 @@ UnlistenStmt: *****************************************************************************/ TransactionStmt: - ABORT_P opt_transaction + ABORT_P opt_transaction opt_transaction_chain { TransactionStmt *n = makeNode(TransactionStmt); n->kind = TRANS_STMT_ROLLBACK; n->options = NIL; + n->chain = $3; $$ = (Node *)n; } | BEGIN_P opt_transaction transaction_mode_list_or_empty @@ -9847,25 +9849,28 @@ TransactionStmt: n->options = $3; $$ = (Node *)n; } - | COMMIT opt_transaction + | COMMIT opt_transaction opt_transaction_chain { TransactionStmt *n = makeNode(TransactionStmt); n->kind = TRANS_STMT_COMMIT; n->options = NIL; + n->chain = $3; $$ = (Node *)n; } - | END_P opt_transaction + | END_P opt_transaction opt_transaction_chain { TransactionStmt *n = makeNode(TransactionStmt); n->kind = TRANS_STMT_COMMIT; n->options = NIL; + n->chain = $3; $$ = (Node *)n; } - | ROLLBACK opt_transaction + | ROLLBACK opt_transaction opt_transaction_chain { TransactionStmt *n = makeNode(TransactionStmt); n->kind = TRANS_STMT_ROLLBACK; n->options = NIL; + n->chain = $3; $$ = (Node *)n; } | SAVEPOINT ColId @@ -9965,6 +9970,12 @@ transaction_mode_list_or_empty: { $$ = NIL; } ; +opt_transaction_chain: + AND CHAIN { $$ = true; } + | AND NO CHAIN { $$ = false; } + | /* EMPTY */ { $$ = false; } + ; + /***************************************************************************** * diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 2d29778787..35d21c23d5 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -434,7 +434,7 @@ standard_ProcessUtility(PlannedStmt *pstmt, break; case TRANS_STMT_COMMIT: - if (!EndTransactionBlock()) + if (!EndTransactionBlock(stmt->chain)) { /* report unsuccessful commit in completionTag */ if (completionTag) @@ -465,7 +465,7 @@ standard_ProcessUtility(PlannedStmt *pstmt, break; case TRANS_STMT_ROLLBACK: - UserAbortTransactionBlock(); + UserAbortTransactionBlock(stmt->chain); break; case TRANS_STMT_SAVEPOINT: diff --git a/src/include/access/xact.h b/src/include/access/xact.h index 87ae2cd4df..12db48c6b8 100644 --- a/src/include/access/xact.h +++ b/src/include/access/xact.h @@ -349,9 +349,9 @@ extern void StartTransactionCommand(void); extern void CommitTransactionCommand(void); extern void AbortCurrentTransaction(void); extern void BeginTransactionBlock(void); -extern bool EndTransactionBlock(void); +extern bool EndTransactionBlock(bool chain); extern bool PrepareTransactionBlock(const char *gid); -extern void UserAbortTransactionBlock(void); +extern void UserAbortTransactionBlock(bool chain); extern void BeginImplicitTransactionBlock(void); extern void EndImplicitTransactionBlock(void); extern void ReleaseSavepoint(const char *name); diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index e3a63e9db4..391b1033d6 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -2967,6 +2967,7 @@ typedef struct TransactionStmt List *options; /* for BEGIN/START commands */ char *savepoint_name; /* for savepoint commands */ char *gid; /* for two-phase-commit related commands */ + bool chain; /* AND CHAIN option */ } TransactionStmt; /* ---------------------- diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out index fa7fccc63b..4b4272b4e9 100644 --- a/src/test/regress/expected/transactions.out +++ b/src/test/regress/expected/transactions.out @@ -659,6 +659,145 @@ ERROR: portal "ctt" cannot be run COMMIT; DROP FUNCTION create_temp_tab(); DROP FUNCTION invert(x float8); +-- Tests for AND CHAIN +CREATE TABLE abc (a int); +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES (1); +INSERT INTO abc VALUES (2); +COMMIT AND CHAIN; -- TBLOCK_END +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES ('error'); +ERROR: invalid input syntax for integer: "error" +LINE 1: INSERT INTO abc VALUES ('error'); + ^ +INSERT INTO abc VALUES (3); -- check it's really aborted +ERROR: current transaction is aborted, commands ignored until end of transaction block +COMMIT AND CHAIN; -- TBLOCK_ABORT_END +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES (3); +COMMIT; +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +SAVEPOINT x; +INSERT INTO abc VALUES ('error'); +ERROR: invalid input syntax for integer: "error" +LINE 1: INSERT INTO abc VALUES ('error'); + ^ +COMMIT AND CHAIN; -- TBLOCK_ABORT_PENDING +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES (4); +COMMIT; +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES (5); +ROLLBACK AND CHAIN; -- TBLOCK_ABORT_PENDING +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +INSERT INTO abc VALUES ('error'); +ERROR: invalid input syntax for integer: "error" +LINE 1: INSERT INTO abc VALUES ('error'); + ^ +ROLLBACK AND CHAIN; -- TBLOCK_ABORT_END +SHOW transaction_isolation; + transaction_isolation +----------------------- + repeatable read +(1 row) + +SHOW transaction_deferrable; + transaction_deferrable +------------------------ + on +(1 row) + +ROLLBACK; +SELECT * FROM abc ORDER BY 1; + a +--- + 1 + 2 + 3 + 4 +(4 rows) + +DROP TABLE abc; -- Test assorted behaviors around the implicit transaction block created -- when multiple SQL commands are sent in a single Query message. These -- tests rely on the fact that psql will not break SQL commands apart at a diff --git a/src/test/regress/sql/transactions.sql b/src/test/regress/sql/transactions.sql index 82661ab610..4d56fab464 100644 --- a/src/test/regress/sql/transactions.sql +++ b/src/test/regress/sql/transactions.sql @@ -419,6 +419,55 @@ CREATE FUNCTION create_temp_tab() RETURNS text DROP FUNCTION invert(x float8); +-- Tests for AND CHAIN + +CREATE TABLE abc (a int); + +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES (1); +INSERT INTO abc VALUES (2); +COMMIT AND CHAIN; -- TBLOCK_END +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES ('error'); +INSERT INTO abc VALUES (3); -- check it's really aborted +COMMIT AND CHAIN; -- TBLOCK_ABORT_END +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES (3); +COMMIT; + +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; +SHOW transaction_deferrable; +SAVEPOINT x; +INSERT INTO abc VALUES ('error'); +COMMIT AND CHAIN; -- TBLOCK_ABORT_PENDING +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES (4); +COMMIT; + +START TRANSACTION ISOLATION LEVEL REPEATABLE READ, DEFERRABLE; +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES (5); +ROLLBACK AND CHAIN; -- TBLOCK_ABORT_PENDING +SHOW transaction_isolation; +SHOW transaction_deferrable; +INSERT INTO abc VALUES ('error'); +ROLLBACK AND CHAIN; -- TBLOCK_ABORT_END +SHOW transaction_isolation; +SHOW transaction_deferrable; +ROLLBACK; + +SELECT * FROM abc ORDER BY 1; + +DROP TABLE abc; + + -- Test assorted behaviors around the implicit transaction block created -- when multiple SQL commands are sent in a single Query message. These -- tests rely on the fact that psql will not break SQL commands apart at a -- 2.16.2