From e86cfc4bbe198f8c7367e8b23efadae97da64d7c Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Fri, 27 Jun 2014 14:43:45 -0400 Subject: [PATCH] Don't allow relminmxid to go backwards during VACUUM FULL We were allowing a table's pg_class.relminmxid value to move backwards when heaps were swapped by VACUUM FULL or CLUSTER. There is a similar protection against relfrozenxid going backwards, which we neglected to clone when the multixact stuff was rejiggered by commit 0ac5ad5134f276. Backpatch to 9.3, where relminmxid was introduced. As reported by Heikki in http://www.postgresql.org/message-id/52401AEA.9000608@vmware.com --- src/backend/commands/cluster.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 6f87170946c..46b41c17d21 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -873,6 +873,12 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, if (TransactionIdPrecedes(FreezeXid, OldHeap->rd_rel->relfrozenxid)) FreezeXid = OldHeap->rd_rel->relfrozenxid; + /* + * MultiXactCutoff, similarly, shouldn't go backwards either. + */ + if (MultiXactIdPrecedes(MultiXactCutoff, OldHeap->rd_rel->relminmxid)) + MultiXactCutoff = OldHeap->rd_rel->relminmxid; + /* return selected values to caller */ *pFreezeXid = FreezeXid; *pCutoffMulti = MultiXactCutoff;