Remove overzealous MultiXact freeze assertion.

petergeoghegan · petergeoghegan · commit 63c844a0a5d7 · 2022-12-26T23:36:02.000-08:00
When VACUUM determines that an existing MultiXact should use a freeze plan that sets xmax to InvalidTransactionId, the original Multi may or may not be before OldestMxact. Remove an incorrect assertion that expected it to always be from before OldestMxact. Oversight in commit 4ce3af. Author: Peter Geoghegan <pg@bowt.ie> Reported-By: Hayato Kuroda <kuroda.hayato@fujitsu.com> Discussion: https://postgr.es/m/TYAPR01MB5866B24104FD80B5D7E65C3EF5ED9@TYAPR01MB5866.jpnprd01.prod.outlook.com
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
@@ -6615,7 +6615,6 @@ heap_prepare_freeze_tuple(HeapTupleHeader tuple,
 			 * it'll leave nothing in xmax (neither an Xid nor a MultiXactId).
 			 */
 			Assert(flags & FRM_INVALIDATE_XMAX);
-			Assert(MultiXactIdPrecedes(xid, cutoffs->OldestMxact));
 			Assert(!TransactionIdIsValid(newxmax));
 
 			/* Will set t_infomask/t_infomask2 flags in freeze plan below */
