diff options
Diffstat (limited to 'src/backend/commands/cluster.c')
| -rw-r--r-- | src/backend/commands/cluster.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index de71a3594d4..c3deb567626 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -444,7 +444,7 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck, LOCKMOD * might put recently-dead tuples out-of-order in the new table, and there * is little harm in that.) */ - if (!OldIndex->rd_index->indisvalid) + if (!IndexIsValid(OldIndex->rd_index)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot cluster on invalid index \"%s\"", @@ -458,6 +458,11 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck, LOCKMOD * mark_index_clustered: mark the specified index as the one clustered on * * With indexOid == InvalidOid, will mark all indexes of rel not-clustered. + * + * Note: we do transactional updates of the pg_index rows, which are unsafe + * against concurrent SnapshotNow scans of pg_index. Therefore this is unsafe + * to execute with less than full exclusive lock on the parent table; + * otherwise concurrent executions of RelationGetIndexList could miss indexes. */ void mark_index_clustered(Relation rel, Oid indexOid) @@ -513,6 +518,9 @@ mark_index_clustered(Relation rel, Oid indexOid) } else if (thisIndexOid == indexOid) { + /* this was checked earlier, but let's be real sure */ + if (!IndexIsValid(indexForm)) + elog(ERROR, "cannot cluster on invalid index %u", indexOid); indexForm->indisclustered = true; simple_heap_update(pg_index, &indexTuple->t_self, indexTuple); CatalogUpdateIndexes(pg_index, indexTuple); |