From a6542f90f9f720862d4c2b34e6d77efd94a8d47c Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Tue, 3 Aug 2010 15:47:16 +0000 Subject: [PATCH] Fix inheritance count tracking in ALTER TABLE .. ADD CONSTRAINT. Without this patch, constraints inherited by children of a parent table which itself has multiple inheritance parents can end up with the wrong coninhcount. After dropping the constraint, the children end up with a leftover copy of the constraint that is not dumped and cannot be dropped. There is a similar problem with ALTER TABLE .. ADD COLUMN, but that looks significantly more difficult to resolve, so I'm committing this fix separately. Back-patch to 8.4, which is the first release that has coninhcount. Report by Hank Enting. --- src/backend/commands/tablecmds.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index d07e51fb65..da491e14ef 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.288.2.5 2010/07/29 19:23:37 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.288.2.6 2010/08/03 15:47:16 rhaas Exp $ * *------------------------------------------------------------------------- */ @@ -4524,6 +4524,15 @@ ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, /* Advance command counter in case same table is visited multiple times */ CommandCounterIncrement(); + /* + * If the constraint got merged with an existing constraint, we're done. + * We mustn't recurse to child tables in this case, because they've already + * got the constraint, and visiting them again would lead to an incorrect + * value for coninhcount. + */ + if (newcons == NIL) + return; + /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't