From: Robert Haas <rhaas@postgresql.org>
Date: Tue, 28 Mar 2023 20:16:53 +0000 (-0400)
Subject: amcheck: In verify_heapam, allows tuples with xmin 0.
X-Git-Tag: REL_15_3~55
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=453f53821fa549d3e46c87a076fc7849fab9a948;p=thirdparty%2Fpostgresql.git

amcheck: In verify_heapam, allows tuples with xmin 0.

Commit e88754a1965c0f40a723e6e46d670cacda9e19bd caused that case
to be reported as corruption, but Peter Geoghegan pointed out that
it can legitimately happen in the case of a speculative insertion
that aborts, so we'd better not flag it as corruption after all.

Back-patch to v14, like the commit that introduced the issue.

Discussion: http://postgr.es/m/CAH2-WzmEabzcPTxSY-NXKH6Qt3FkAPYHGQSe2PtvGgj17ZQkCw@mail.gmail.com
---

diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c
index 1d186d1e4de..4e3e87aa800 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -739,8 +739,7 @@ check_tuple_visibility(HeapCheckContext *ctx)
 	switch (get_xid_status(xmin, ctx, &xmin_status))
 	{
 		case XID_INVALID:
-			report_corruption(ctx,
-							  pstrdup("xmin is invalid"));
+			/* Could be the result of a speculative insertion that aborted. */
 			return false;
 		case XID_BOUNDS_OK:
 			break;