postgres.git / summary / log / commit / refs
commit a6542f90f9f720862d4c2b34e6d77efd94a8d47c
Author: Robert Haas <rhaas@postgresql.org>
Date: Tue Aug 03 15:47:16 2010 +0000
First released in: 9.1.0, 8.4.5, 9.0.0
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 d07e51fb658..da491e14ef2 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
[parent: 9f4b99afbb38]