From a7b7c4094a54f9b217332809b1abfb521a4b994d Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Fri, 5 Oct 2018 12:24:34 +0200 Subject: [PATCH v2] Advance transaction timestamp in intra-procedure transactions --- src/backend/access/transam/xact.c | 19 +++++++----- .../src/expected/plpgsql_transaction.out | 28 +++++++++++++++++ .../plpgsql/src/sql/plpgsql_transaction.sql | 31 +++++++++++++++++++ 3 files changed, 71 insertions(+), 7 deletions(-) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 9aa63c8792..245735420c 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -1884,14 +1884,19 @@ StartTransaction(void) TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId); /* - * set transaction_timestamp() (a/k/a now()). We want this to be the same - * as the first command's statement_timestamp(), so don't do a fresh - * GetCurrentTimestamp() call (which'd be expensive anyway). Also, mark - * xactStopTimestamp as unset. - */ - xactStartTimestamp = stmtStartTimestamp; - xactStopTimestamp = 0; + * set transaction_timestamp() (a/k/a now()). Normally, we want this to + * be the same as the first command's statement_timestamp(), so don't do a + * fresh GetCurrentTimestamp() call (which'd be expensive anyway). But + * for transactions started inside statements (e.g., procedure calls), we + * want to advance the timestamp. + */ + if (xactStartTimestamp < stmtStartTimestamp) + xactStartTimestamp = stmtStartTimestamp; + else + xactStartTimestamp = GetCurrentTimestamp(); pgstat_report_xact_timestamp(xactStartTimestamp); + /* Mark xactStopTimestamp as unset. */ + xactStopTimestamp = 0; /* * initialize current transaction state fields diff --git a/src/pl/plpgsql/src/expected/plpgsql_transaction.out b/src/pl/plpgsql/src/expected/plpgsql_transaction.out index 77a83adab5..71e56300bc 100644 --- a/src/pl/plpgsql/src/expected/plpgsql_transaction.out +++ b/src/pl/plpgsql/src/expected/plpgsql_transaction.out @@ -493,6 +493,34 @@ CALL transaction_test10b(10); 9 (1 row) +-- transaction timestamp vs. statement timestamp +CREATE PROCEDURE transaction_test11() +LANGUAGE plpgsql +AS $$ +DECLARE + s1 timestamp with time zone; + s2 timestamp with time zone; + s3 timestamp with time zone; + t1 timestamp with time zone; + t2 timestamp with time zone; + t3 timestamp with time zone; +BEGIN + s1 := statement_timestamp(); + t1 := transaction_timestamp(); + ASSERT s1 = t1; + COMMIT; + s2 := statement_timestamp(); + t2 := transaction_timestamp(); + ASSERT s2 = s1; + ASSERT t2 > t1; + ROLLBACK; + s3 := statement_timestamp(); + t3 := transaction_timestamp(); + ASSERT s3 = s1; + ASSERT t3 > t2; +END; +$$; +CALL transaction_test11(); DROP TABLE test1; DROP TABLE test2; DROP TABLE test3; diff --git a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql index 0ed9ab873a..e2089f56ad 100644 --- a/src/pl/plpgsql/src/sql/plpgsql_transaction.sql +++ b/src/pl/plpgsql/src/sql/plpgsql_transaction.sql @@ -412,6 +412,37 @@ CREATE PROCEDURE transaction_test10b(INOUT x int) CALL transaction_test10b(10); +-- transaction timestamp vs. statement timestamp +CREATE PROCEDURE transaction_test11() +LANGUAGE plpgsql +AS $$ +DECLARE + s1 timestamp with time zone; + s2 timestamp with time zone; + s3 timestamp with time zone; + t1 timestamp with time zone; + t2 timestamp with time zone; + t3 timestamp with time zone; +BEGIN + s1 := statement_timestamp(); + t1 := transaction_timestamp(); + ASSERT s1 = t1; + COMMIT; + s2 := statement_timestamp(); + t2 := transaction_timestamp(); + ASSERT s2 = s1; + ASSERT t2 > t1; + ROLLBACK; + s3 := statement_timestamp(); + t3 := transaction_timestamp(); + ASSERT s3 = s1; + ASSERT t3 > t2; +END; +$$; + +CALL transaction_test11(); + + DROP TABLE test1; DROP TABLE test2; DROP TABLE test3; base-commit: ff347f8aff04865680c19ffc818460bb2afaad5b -- 2.19.0