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help / color / mirror / Atom feedFrom: Melanie Plageman <[email protected]>
Subject: [PATCH v6 01/14] BitmapHeapScan begin scan after bitmap creation
Date: Mon, 12 Feb 2024 18:50:29 -0500
There is no reason for a BitmapHeapScan to begin the scan of the
underlying table in ExecInitBitmapHeapScan(). Instead, do so after
completing the index scan and building the bitmap.
---
src/backend/access/table/tableam.c | 1 -
src/backend/executor/nodeBitmapHeapscan.c | 26 +++++++++++++++++------
2 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c
index e57a0b7ea31..e78d793f69c 100644
--- a/src/backend/access/table/tableam.c
+++ b/src/backend/access/table/tableam.c
@@ -120,7 +120,6 @@ table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key)
NULL, flags);
}
-
/* ----------------------------------------------------------------------------
* Parallel table scan related functions.
* ----------------------------------------------------------------------------
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index ca548e44eb4..6d756001fdb 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -178,6 +178,20 @@ BitmapHeapNext(BitmapHeapScanState *node)
}
#endif /* USE_PREFETCH */
}
+
+ /*
+ * If this is the first scan of the underlying table, create the table
+ * scan descriptor and begin the scan.
+ */
+ if (!scan)
+ {
+ scan = node->ss.ss_currentScanDesc = table_beginscan_bm(
+ node->ss.ss_currentRelation,
+ node->ss.ps.state->es_snapshot,
+ 0,
+ NULL);
+ }
+
node->initialized = true;
}
@@ -601,7 +615,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node)
PlanState *outerPlan = outerPlanState(node);
/* rescan to release any page pin */
- table_rescan(node->ss.ss_currentScanDesc, NULL);
+ if (node->ss.ss_currentScanDesc)
+ table_rescan(node->ss.ss_currentScanDesc, NULL);
/* release bitmaps and buffers if any */
if (node->tbmiterator)
@@ -678,7 +693,9 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node)
/*
* close heap scan
*/
- table_endscan(scanDesc);
+ if (scanDesc)
+ table_endscan(scanDesc);
+
}
/* ----------------------------------------------------------------
@@ -783,11 +800,6 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
scanstate->ss.ss_currentRelation = currentRelation;
- scanstate->ss.ss_currentScanDesc = table_beginscan_bm(currentRelation,
- estate->es_snapshot,
- 0,
- NULL);
-
/*
* all done.
*/
--
2.40.1
--w4wcjcocxsm37usi
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v6-0002-BitmapHeapScan-set-can_skip_fetch-later.patch"
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