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-Url: http://git.postgresql.org/gitweb/-?a=commitdiff_plain;h=b7cea58822c67724effc711ae28e4077a01a7cd6;p=users%2Frhaas%2Fpostgres.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 ce3114f4e6..f50ee9d29f 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -1032,8 +1032,7 @@ check_tuple_visibility(HeapCheckContext *ctx, bool *xmin_commit_status_ok,
 	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:
 			*xmin_commit_status_ok = true;