From 2c535bfe81ad7cd77d561cd92c441a4787047aa1 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 17 Jul 2007 17:45:28 +0000 Subject: [PATCH] Fix incorrect optimization of foreign-key checks. When an UPDATE on the referencing table does not change the tuple's FK column(s), we don't bother to check the PK table since the constraint was presumably already valid. However, the check is still necessary if the tuple was inserted by our own transaction, since in that case the INSERT trigger will conclude it need not make the check (since its version of the tuple has been deleted). We got this right for simple cases, but not when the insert and update are in different subtransactions of the current top-level transaction; in such cases the FK check would never be made at all. (Hence, problem dates back to 8.0 when subtransactions were added --- it's actually the subtransaction version of a bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by Affan Salman. --- src/backend/commands/trigger.c | 5 +-- src/test/regress/expected/foreign_key.out | 37 +++++++++++++++++ src/test/regress/sql/foreign_key.sql | 49 +++++++++++++++++++++++ 3 files changed, 88 insertions(+), 3 deletions(-) diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 3f251ad6dd..80b28f5e4b 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.215 2007/07/01 17:45:42 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.216 2007/07/17 17:45:28 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -3396,8 +3396,7 @@ AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger, * anything, so we have to do the check for the UPDATE * anyway. */ - if (HeapTupleHeaderGetXmin(oldtup->t_data) != - GetCurrentTransactionId() && + if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(oldtup->t_data)) && RI_FKey_keyequal_upd_fk(trigger, rel, oldtup, newtup)) { continue; diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out index 3c0dd7f087..56411f06a3 100644 --- a/src/test/regress/expected/foreign_key.out +++ b/src/test/regress/expected/foreign_key.out @@ -1193,3 +1193,40 @@ UPDATE fktable SET id = id + 1; COMMIT; ERROR: insert or update on table "fktable" violates foreign key constraint "fktable_fk_fkey" DETAIL: Key (fk)=(20) is not present in table "pktable". +-- check same case when insert is in a different subtransaction than update +BEGIN; +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); +-- UPDATE will be in a subxact +SAVEPOINT savept1; +-- don't change FK +UPDATE fktable SET id = id + 1; +-- should catch error from initial INSERT +COMMIT; +ERROR: insert or update on table "fktable" violates foreign key constraint "fktable_fk_fkey" +DETAIL: Key (fk)=(20) is not present in table "pktable". +BEGIN; +-- INSERT will be in a subxact +SAVEPOINT savept1; +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); +RELEASE SAVEPOINT savept1; +-- don't change FK +UPDATE fktable SET id = id + 1; +-- should catch error from initial INSERT +COMMIT; +ERROR: insert or update on table "fktable" violates foreign key constraint "fktable_fk_fkey" +DETAIL: Key (fk)=(20) is not present in table "pktable". +BEGIN; +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); +-- UPDATE will be in a subxact +SAVEPOINT savept1; +-- don't change FK +UPDATE fktable SET id = id + 1; +-- Roll back the UPDATE +ROLLBACK TO savept1; +-- should catch error from initial INSERT +COMMIT; +ERROR: insert or update on table "fktable" violates foreign key constraint "fktable_fk_fkey" +DETAIL: Key (fk)=(20) is not present in table "pktable". diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql index 5a0140c280..1ab557b9bf 100644 --- a/src/test/regress/sql/foreign_key.sql +++ b/src/test/regress/sql/foreign_key.sql @@ -830,3 +830,52 @@ UPDATE fktable SET id = id + 1; -- should catch error from initial INSERT COMMIT; + +-- check same case when insert is in a different subtransaction than update + +BEGIN; + +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); + +-- UPDATE will be in a subxact +SAVEPOINT savept1; + +-- don't change FK +UPDATE fktable SET id = id + 1; + +-- should catch error from initial INSERT +COMMIT; + +BEGIN; + +-- INSERT will be in a subxact +SAVEPOINT savept1; + +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); + +RELEASE SAVEPOINT savept1; + +-- don't change FK +UPDATE fktable SET id = id + 1; + +-- should catch error from initial INSERT +COMMIT; + +BEGIN; + +-- doesn't match PK, but no error yet +INSERT INTO fktable VALUES (0, 20); + +-- UPDATE will be in a subxact +SAVEPOINT savept1; + +-- don't change FK +UPDATE fktable SET id = id + 1; + +-- Roll back the UPDATE +ROLLBACK TO savept1; + +-- should catch error from initial INSERT +COMMIT; -- 2.40.0