v20240124-0002-fixup.patch

From 864f40d357cf3f6667553c6e7d312ac047e9f8ce Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas@2ndquadrant.com>
Date: Wed, 24 Jan 2024 14:09:33 +0100
Subject: [PATCH v20240124 2/2] fixup

---
 src/backend/executor/nodeIndexonlyscan.c | 28 +++++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c
index fce10ea6518..9f75649270f 100644
--- a/src/backend/executor/nodeIndexonlyscan.c
+++ b/src/backend/executor/nodeIndexonlyscan.c
@@ -54,6 +54,11 @@ static IndexPrefetchEntry *IndexOnlyPrefetchNext(IndexScanDesc scan,
 static void IndexOnlyPrefetchCleanup(IndexScanDesc scan,
 									 void *data);
 
+typedef struct IndexOnlyPrefetchInfo {
+	bool		all_visible;
+	IndexTuple	index_tuple;
+} IndexOnlyPrefetchInfo;
+
 /* ----------------------------------------------------------------
  *		IndexOnlyNext
  *
@@ -146,12 +151,14 @@ IndexOnlyNext(IndexOnlyScanState *node)
 	 */
 	while ((entry = IndexPrefetchNext(scandesc, prefetch, direction)) != NULL)
 	{
-		bool	   *all_visible = NULL;
+		IndexOnlyPrefetchInfo	*info;
 		bool		tuple_from_heap = false;
 
 		/* unpack the entry */
 		tid = &entry->tid;
-		all_visible = (bool *) entry->data; /* result of visibility check */
+
+		/* result of visibility check and index tuple */
+		info = (IndexOnlyPrefetchInfo *) entry->data;
 
 		CHECK_FOR_INTERRUPTS();
 
@@ -192,7 +199,7 @@ IndexOnlyNext(IndexOnlyScanState *node)
 		 * XXX Skip if we already know the page is all visible from
 		 * prefetcher.
 		 */
-		if (!(all_visible && *all_visible) &&
+		if (!(info && info->all_visible) &&
 			!VM_ALL_VISIBLE(scandesc->heapRelation,
 							ItemPointerGetBlockNumber(tid),
 							&node->ioss_VMBuffer))
@@ -224,6 +231,8 @@ IndexOnlyNext(IndexOnlyScanState *node)
 
 			tuple_from_heap = true;
 		}
+		else if (info)
+			scandesc->xs_itup = info->index_tuple;
 
 		/*
 		 * Fill the scan tuple slot with data from the index.  This might be
@@ -782,6 +791,7 @@ IndexOnlyPrefetchNext(IndexScanDesc scan, ScanDirection direction, void *data)
 
 	if ((tid = index_getnext_tid(scan, direction)) != NULL)
 	{
+		IndexOnlyPrefetchInfo *info;
 		BlockNumber blkno = ItemPointerGetBlockNumber(tid);
 
 		bool		all_visible = VM_ALL_VISIBLE(scan->heapRelation,
@@ -795,9 +805,15 @@ IndexOnlyPrefetchNext(IndexScanDesc scan, ScanDirection direction, void *data)
 		/* prefetch only if not all visible */
 		entry->prefetch = !all_visible;
 
-		/* store the all_visible flag in the private part of the entry */
-		entry->data = palloc(sizeof(bool));
-		*(bool *) entry->data = all_visible;
+		/*
+		 * Store the index tuple and all-visible flag in the private part
+		 * of the entry.
+		 */
+		info = palloc(sizeof(IndexOnlyPrefetchInfo));
+		info->all_visible = all_visible;
+		info->index_tuple = CopyIndexTuple(scan->xs_itup);
+
+		entry->data = info;
 	}
 
 	return entry;
-- 
2.43.0