index 530d924bff85359caa8fe681fbdbd250a6b63d3c..ef48679cc2eb03b093be3e22625262f55a742985 100644 (file)
@@ -2791,10 +2791,26 @@ _bt_lock_subtree_parent(Relation rel, BlockNumber child, BTStack stack,
*/
pbuf = _bt_getstackbuf(rel, stack, child);
if (pbuf == InvalidBuffer)
- ereport(ERROR,
+ {
+ /*
+ * Failed to "re-find" a pivot tuple whose downlink matched our child
+ * block number on the parent level -- the index must be corrupt.
+ * Don't even try to delete the leafbuf subtree. Just report the
+ * issue and press on with vacuuming the index.
+ *
+ * Note: _bt_getstackbuf() recovers from concurrent page splits that
+ * take place on the parent level. Its approach is a near-exhaustive
+ * linear search. This also gives it a surprisingly good chance of
+ * recovering in the event of a buggy or inconsistent opclass. But we
+ * don't rely on that here.
+ */
+ ereport(LOG,
(errcode(ERRCODE_INDEX_CORRUPTED),
errmsg_internal("failed to re-find parent key in index \"%s\" for deletion target page %u",
RelationGetRelationName(rel), child)));
+ return false;
+ }
+
parent = stack->bts_blkno;
parentoffset = stack->bts_offset;