From dd0183469bb779247c96e86c2272dca7ff4ec9e7 Mon Sep 17 00:00:00 2001 From: Noah Misch Date: Mon, 29 Apr 2024 10:25:33 -0700 Subject: Avoid repeating loads of frozen ID values. Repeating loads of inplace-updated fields tends to cause bugs like the one from the previous commit. While there's no bug to fix in these code sites, adopt the load-once style. This improves the chance of future copy/paste finding the safe style. Discussion: https://postgr.es/m/20240423003956.e7.nmisch@google.com --- src/backend/commands/cluster.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'src/backend/commands/cluster.c') diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index c04886c4090..78f96789b0e 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -919,18 +919,24 @@ copy_table_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose, * FreezeXid will become the table's new relfrozenxid, and that mustn't go * backwards, so take the max. */ - if (TransactionIdIsValid(OldHeap->rd_rel->relfrozenxid) && - TransactionIdPrecedes(cutoffs.FreezeLimit, - OldHeap->rd_rel->relfrozenxid)) - cutoffs.FreezeLimit = OldHeap->rd_rel->relfrozenxid; + { + TransactionId relfrozenxid = OldHeap->rd_rel->relfrozenxid; + + if (TransactionIdIsValid(relfrozenxid) && + TransactionIdPrecedes(cutoffs.FreezeLimit, relfrozenxid)) + cutoffs.FreezeLimit = relfrozenxid; + } /* * MultiXactCutoff, similarly, shouldn't go backwards either. */ - if (MultiXactIdIsValid(OldHeap->rd_rel->relminmxid) && - MultiXactIdPrecedes(cutoffs.MultiXactCutoff, - OldHeap->rd_rel->relminmxid)) - cutoffs.MultiXactCutoff = OldHeap->rd_rel->relminmxid; + { + MultiXactId relminmxid = OldHeap->rd_rel->relminmxid; + + if (MultiXactIdIsValid(relminmxid) && + MultiXactIdPrecedes(cutoffs.MultiXactCutoff, relminmxid)) + cutoffs.MultiXactCutoff = relminmxid; + } /* * Decide whether to use an indexscan or seqscan-and-optional-sort to scan -- cgit v1.2.3