Movatterモバイル変換


[0]ホーム

URL:


Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Sign up
Appearance settings

Commit1145c26

Browse files
committed
Advance transaction timestamp for intra-procedure transactions.
Per discussion, this behavior seems less astonishing than not doing so.Peter Eisentraut and Tom LaneDiscussion:https://postgr.es/m/20180920234040.GC29981@momjian.us
1 parent8569ef6 commit1145c26

File tree

5 files changed

+91
-8
lines changed

5 files changed

+91
-8
lines changed

‎src/backend/access/transam/xact.c

Lines changed: 14 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1906,20 +1906,26 @@ StartTransaction(void)
19061906
TRACE_POSTGRESQL_TRANSACTION_START(vxid.localTransactionId);
19071907

19081908
/*
1909-
* set transaction_timestamp() (a/k/a now()). We want this to be the same
1910-
* as the first command's statement_timestamp(), so don't do a fresh
1911-
* GetCurrentTimestamp() call (which'd be expensive anyway). In a
1912-
* parallel worker, this should already have been provided by a call to
1909+
* set transaction_timestamp() (a/k/a now()). Normally, we want this to
1910+
* be the same as the first command's statement_timestamp(), so don't do a
1911+
* fresh GetCurrentTimestamp() call (which'd be expensive anyway). But
1912+
* for transactions started inside procedures (i.e., nonatomic SPI
1913+
* contexts), we do need to advance the timestamp. Also, in a parallel
1914+
* worker, the timestamp should already have been provided by a call to
19131915
* SetParallelStartTimestamps().
1914-
*
1915-
* Also, mark xactStopTimestamp as unset.
19161916
*/
19171917
if (!IsParallelWorker())
1918-
xactStartTimestamp=stmtStartTimestamp;
1918+
{
1919+
if (!SPI_inside_nonatomic_context())
1920+
xactStartTimestamp=stmtStartTimestamp;
1921+
else
1922+
xactStartTimestamp=GetCurrentTimestamp();
1923+
}
19191924
else
19201925
Assert(xactStartTimestamp!=0);
1921-
xactStopTimestamp=0;
19221926
pgstat_report_xact_timestamp(xactStartTimestamp);
1927+
/* Mark xactStopTimestamp as unset. */
1928+
xactStopTimestamp=0;
19231929

19241930
/*
19251931
* initialize current transaction state fields

‎src/backend/executor/spi.c

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -423,6 +423,19 @@ AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
423423
}
424424
}
425425

426+
/*
427+
* Are we executing inside a procedure (that is, a nonatomic SPI context)?
428+
*/
429+
bool
430+
SPI_inside_nonatomic_context(void)
431+
{
432+
if (_SPI_current==NULL)
433+
return false;/* not in any SPI context at all */
434+
if (_SPI_current->atomic)
435+
return false;/* it's atomic (ie function not procedure) */
436+
return true;
437+
}
438+
426439

427440
/* Parse, plan, and execute a query string */
428441
int

‎src/include/executor/spi.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -166,5 +166,6 @@ extern void SPI_rollback(void);
166166
externvoidSPICleanup(void);
167167
externvoidAtEOXact_SPI(boolisCommit);
168168
externvoidAtEOSubXact_SPI(boolisCommit,SubTransactionIdmySubid);
169+
externboolSPI_inside_nonatomic_context(void);
169170

170171
#endif/* SPI_H */

‎src/pl/plpgsql/src/expected/plpgsql_transaction.out

Lines changed: 30 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -493,6 +493,36 @@ CALL transaction_test10b(10);
493493
9
494494
(1 row)
495495

496+
-- transaction timestamp vs. statement timestamp
497+
CREATE PROCEDURE transaction_test11()
498+
LANGUAGE plpgsql
499+
AS $$
500+
DECLARE
501+
s1 timestamp with time zone;
502+
s2 timestamp with time zone;
503+
s3 timestamp with time zone;
504+
t1 timestamp with time zone;
505+
t2 timestamp with time zone;
506+
t3 timestamp with time zone;
507+
BEGIN
508+
s1 := statement_timestamp();
509+
t1 := transaction_timestamp();
510+
ASSERT s1 = t1;
511+
PERFORM pg_sleep(0.001);
512+
COMMIT;
513+
s2 := statement_timestamp();
514+
t2 := transaction_timestamp();
515+
ASSERT s2 = s1;
516+
ASSERT t2 > t1;
517+
PERFORM pg_sleep(0.001);
518+
ROLLBACK;
519+
s3 := statement_timestamp();
520+
t3 := transaction_timestamp();
521+
ASSERT s3 = s1;
522+
ASSERT t3 > t2;
523+
END;
524+
$$;
525+
CALL transaction_test11();
496526
DROP TABLE test1;
497527
DROP TABLE test2;
498528
DROP TABLE test3;

‎src/pl/plpgsql/src/sql/plpgsql_transaction.sql

Lines changed: 33 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -412,6 +412,39 @@ $$;
412412
CALL transaction_test10b(10);
413413

414414

415+
-- transaction timestamp vs. statement timestamp
416+
CREATE PROCEDURE transaction_test11()
417+
LANGUAGE plpgsql
418+
AS $$
419+
DECLARE
420+
s1timestamp with time zone;
421+
s2timestamp with time zone;
422+
s3timestamp with time zone;
423+
t1timestamp with time zone;
424+
t2timestamp with time zone;
425+
t3timestamp with time zone;
426+
BEGIN
427+
s1 := statement_timestamp();
428+
t1 := transaction_timestamp();
429+
ASSERT s1= t1;
430+
PERFORM pg_sleep(0.001);
431+
COMMIT;
432+
s2 := statement_timestamp();
433+
t2 := transaction_timestamp();
434+
ASSERT s2= s1;
435+
ASSERT t2> t1;
436+
PERFORM pg_sleep(0.001);
437+
ROLLBACK;
438+
s3 := statement_timestamp();
439+
t3 := transaction_timestamp();
440+
ASSERT s3= s1;
441+
ASSERT t3> t2;
442+
END;
443+
$$;
444+
445+
CALL transaction_test11();
446+
447+
415448
DROPTABLE test1;
416449
DROPTABLE test2;
417450
DROPTABLE test3;

0 commit comments

Comments
 (0)

[8]ページ先頭

©2009-2025 Movatter.jp