v1-0008-Reduce-scope-of-BitmapHeapScan-tbmiterator-local-.patch

From ccd5d688fd5c1dd16908788e0a0abd0f3e64eb77 Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplageman@gmail.com>
Date: Tue, 13 Feb 2024 10:17:47 -0500
Subject: [PATCH v1 08/11] Reduce scope of BitmapHeapScan tbmiterator local
 variables

To simplify the diff of a future commit which will move the TBMIterators
into the scan descriptor, define them in a narrower scope now.
---
 src/backend/executor/nodeBitmapHeapscan.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 19d115de06f..4d55390715c 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -76,8 +76,6 @@ BitmapHeapNext(BitmapHeapScanState *node)
 	ExprContext *econtext;
 	TableScanDesc scan;
 	TIDBitmap  *tbm;
-	TBMIterator *tbmiterator = NULL;
-	TBMSharedIterator *shared_tbmiterator = NULL;
 	TBMIterateResult *tbmres;
 	TupleTableSlot *slot;
 	ParallelBitmapHeapState *pstate = node->pstate;
@@ -90,10 +88,6 @@ BitmapHeapNext(BitmapHeapScanState *node)
 	slot = node->ss.ss_ScanTupleSlot;
 	scan = node->ss.ss_currentScanDesc;
 	tbm = node->tbm;
-	if (pstate == NULL)
-		tbmiterator = node->tbmiterator;
-	else
-		shared_tbmiterator = node->shared_tbmiterator;
 	tbmres = node->tbmres;
 
 	/*
@@ -111,6 +105,8 @@ BitmapHeapNext(BitmapHeapScanState *node)
 	if (!node->initialized)
 	{
 		bool can_skip_fetch;
+		TBMIterator *tbmiterator = NULL;
+		TBMSharedIterator *shared_tbmiterator = NULL;
 		/*
 		 * We can potentially skip fetching heap pages if we do not need any
 		 * columns of the table, either for checking non-indexable quals or
@@ -129,7 +125,7 @@ BitmapHeapNext(BitmapHeapScanState *node)
 				elog(ERROR, "unrecognized result from subplan");
 
 			node->tbm = tbm;
-			node->tbmiterator = tbmiterator = tbm_begin_iterate(tbm);
+			tbmiterator = tbm_begin_iterate(tbm);
 			node->tbmres = tbmres = NULL;
 
 #ifdef USE_PREFETCH
@@ -182,8 +178,7 @@ BitmapHeapNext(BitmapHeapScanState *node)
 			}
 
 			/* Allocate a private iterator and attach the shared state to it */
-			node->shared_tbmiterator = shared_tbmiterator =
-				tbm_attach_shared_iterate(dsa, pstate->tbmiterator);
+			shared_tbmiterator = tbm_attach_shared_iterate(dsa, pstate->tbmiterator);
 			node->tbmres = tbmres = NULL;
 
 #ifdef USE_PREFETCH
@@ -206,6 +201,8 @@ BitmapHeapNext(BitmapHeapScanState *node)
 																	can_skip_fetch);
 		}
 
+		node->tbmiterator = tbmiterator;
+		node->shared_tbmiterator = shared_tbmiterator;
 		node->initialized = true;
 	}
 
@@ -219,9 +216,9 @@ BitmapHeapNext(BitmapHeapScanState *node)
 		if (tbmres == NULL)
 		{
 			if (!pstate)
-				node->tbmres = tbmres = tbm_iterate(tbmiterator);
+				node->tbmres = tbmres = tbm_iterate(node->tbmiterator);
 			else
-				node->tbmres = tbmres = tbm_shared_iterate(shared_tbmiterator);
+				node->tbmres = tbmres = tbm_shared_iterate(node->shared_tbmiterator);
 			if (tbmres == NULL)
 			{
 				/* no more entries in the bitmap */
-- 
2.37.2