From 60e75bbf91bf06832402daa5d3c30bc99401c2f2 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Tue, 13 Feb 2024 14:38:41 -0500 Subject: [PATCH v19 02/21] BitmapHeapScan: postpone setting can_skip_fetch Set BitmapHeapScanState->can_skip_fetch in BitmapHeapNext() instead of in ExecInitBitmapHeapScan(). This is a preliminary step to pushing the skip fetch optimization into heap AM code. Author: Melanie Plageman Reviewed-by: Tomas Vondra, Andres Freund, Heikki Linnakangas Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index c8c466e3c5c..2148a21531a 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -105,6 +105,16 @@ BitmapHeapNext(BitmapHeapScanState *node) */ if (!node->initialized) { + /* + * We can potentially skip fetching heap pages if we do not need any + * columns of the table, either for checking non-indexable quals or + * for returning data. This test is a bit simplistic, as it checks + * the stronger condition that there's no qual or return tlist at all. + * But in most cases it's probably not worth working harder than that. + */ + node->can_skip_fetch = (node->ss.ps.plan->qual == NIL && + node->ss.ps.plan->targetlist == NIL); + if (!pstate) { tbm = (TIDBitmap *) MultiExecProcNode(outerPlanState(node)); @@ -743,16 +753,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->shared_tbmiterator = NULL; scanstate->shared_prefetch_iterator = NULL; scanstate->pstate = 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 for - * returning data. This test is a bit simplistic, as it checks the - * stronger condition that there's no qual or return tlist at all. But in - * most cases it's probably not worth working harder than that. - */ - scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && - node->scan.plan.targetlist == NIL); + scanstate->can_skip_fetch = false; /* * Miscellaneous initialization -- 2.40.1