Fix amcheck's handling of half-dead B-tree pages

hlinnaka · hlinnaka · commit fbb4b607832d · 2025-12-02T21:16:17.000+02:00
amcheck incorrectly reported the following error if there were any half-dead pages in the index: ERROR: mismatch between parent key and child high key in index "amchecktest_id_idx" It's expected that a half-dead page does not have a downlink in the parent level, so skip the test. Reported-by: Konstantin Knizhnik <knizhnik@garret.ru> Reviewed-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Mihail Nikalayeu <mihailnikalayeu@gmail.com> Discussion: https://www.postgresql.org/message-id/33e39552-6a2a-46f3-8b34-3f9f8004451f@garret.ru Backpatch-through: 14
diff --git a/contrib/amcheck/verify_nbtree.c b/contrib/amcheck/verify_nbtree.c
@@ -2047,7 +2047,7 @@ bt_child_highkey_check(BtreeCheckState *state,
 		 * If we visit page with high key, check that it is equal to the
 		 * target key next to corresponding downlink.
 		 */
-		if (!rightsplit && !P_RIGHTMOST(opaque))
+		if (!rightsplit && !P_RIGHTMOST(opaque) && !P_ISHALFDEAD(opaque))
 		{
 			BTPageOpaque topaque;
 			IndexTuple	highkey;

Original file line number	Diff line number	Diff line change
`@@ -2047,7 +2047,7 @@ bt_child_highkey_check(BtreeCheckState *state,`
`2047`	`2047`	`* If we visit page with high key, check that it is equal to the`
`2048`	`2048`	`* target key next to corresponding downlink.`
`2049`	`2049`	`*/`
`2050`		`- if (!rightsplit && !P_RIGHTMOST(opaque))`
	`2050`	`+ if (!rightsplit && !P_RIGHTMOST(opaque) && !P_ISHALFDEAD(opaque))`
`2051`	`2051`	`{`
`2052`	`2052`	`BTPageOpaque topaque;`
`2053`	`2053`	`IndexTuple highkey;`