Fix corner-case bug introduced with HOT: if REINDEX TABLE pg_class (or a

REINDEX DATABASE including same) is done before a session has done any other
update on pg_class, the pg_class relcache entry was left with an incorrect
setting of rd_indexattr, because the indexed-attributes set would be first
demanded at a time when we'd forced a partial list of indexes into the
pg_class entry, and it would remain cached after that.  This could result
in incorrect decisions about HOT-update safety later in the same session.
In practice, since only pg_class_relname_nsp_index would be missed out,
only ALTER TABLE RENAME and ALTER TABLE SET SCHEMA could trigger a problem.
Per report and test case from Ondrej Jirman.
This commit is contained in:
Tom Lane 2008-08-10 19:02:33 +00:00
parent 30fd8ec799
commit eca1388629
2 changed files with 14 additions and 4 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.300 2008/06/19 00:46:04 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.301 2008/08/10 19:02:33 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -2380,9 +2380,13 @@ reindex_relation(Oid relid, bool toast_too)
* problem.
*/
is_pg_class = (RelationGetRelid(rel) == RelationRelationId);
doneIndexes = NIL;
/* Ensure rd_indexattr is valid; see comments for RelationSetIndexList */
if (is_pg_class)
(void) RelationGetIndexAttrBitmap(rel);
/* Reindex all the indexes. */
doneIndexes = NIL;
foreach(indexId, indexIds)
{
Oid indexOid = lfirst_oid(indexId);

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.272 2008/05/12 00:00:52 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.273 2008/08/10 19:02:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2986,6 +2986,13 @@ insert_ordered_oid(List *list, Oid datum)
* messages. In practice it is only used on pg_class (see REINDEX).
*
* It is up to the caller to make sure the given list is correctly ordered.
*
* We deliberately do not change rd_indexattr here: even when operating
* with a temporary partial index list, HOT-update decisions must be made
* correctly with respect to the full index set. It is up to the caller
* to ensure that a correct rd_indexattr set has been cached before first
* calling RelationSetIndexList; else a subsequent inquiry might cause a
* wrong rd_indexattr set to get computed and cached.
*/
void
RelationSetIndexList(Relation relation, List *indexIds, Oid oidIndex)
@ -3004,7 +3011,6 @@ RelationSetIndexList(Relation relation, List *indexIds, Oid oidIndex)
relation->rd_indexvalid = 2; /* mark list as forced */
/* must flag that we have a forced index list */
need_eoxact_work = true;
/* we deliberately do not change rd_indexattr */
}
/*