From 2bb1f14b89deacd1142b4a06bcb1a52a76270449 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Mon, 13 Jan 2014 14:42:16 -0500
Subject: [PATCH] Make bitmap heap scans show exact/lossy block info in EXPLAIN
ANALYZE.
Etsuro Fujita
---
src/backend/commands/explain.c | 33 ++++++++++++++++++++++-
src/backend/executor/nodeBitmapHeapscan.c | 7 +++++
src/include/nodes/execnodes.h | 4 +++
3 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 7097eff9b11..e604be31f9d 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -85,6 +85,8 @@ static void show_sort_group_keys(PlanState *planstate, const char *qlabel,
List *ancestors, ExplainState *es);
static void show_sort_info(SortState *sortstate, ExplainState *es);
static void show_hash_info(HashState *hashstate, ExplainState *es);
+static void show_tidbitmap_info(BitmapHeapScanState *planstate,
+ ExplainState *es);
static void show_instrumentation_count(const char *qlabel, int which,
PlanState *planstate, ExplainState *es);
static void show_foreignscan_info(ForeignScanState *fsstate, ExplainState *es);
@@ -1250,7 +1252,13 @@ ExplainNode(PlanState *planstate, List *ancestors,
if (((BitmapHeapScan *) plan)->bitmapqualorig)
show_instrumentation_count("Rows Removed by Index Recheck", 2,
planstate, es);
- /* FALL THRU */
+ show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
+ if (plan->qual)
+ show_instrumentation_count("Rows Removed by Filter", 1,
+ planstate, es);
+ if (es->analyze)
+ show_tidbitmap_info((BitmapHeapScanState *) planstate, es);
+ break;
case T_SeqScan:
case T_ValuesScan:
case T_CteScan:
@@ -1878,6 +1886,29 @@ show_hash_info(HashState *hashstate, ExplainState *es)
}
}
+/*
+ * If it's EXPLAIN ANALYZE, show exact/lossy pages for a BitmapHeapScan node
+ */
+static void
+show_tidbitmap_info(BitmapHeapScanState *planstate, ExplainState *es)
+{
+ if (es->format != EXPLAIN_FORMAT_TEXT)
+ {
+ ExplainPropertyLong("Exact Heap Blocks", planstate->exact_pages, es);
+ ExplainPropertyLong("Lossy Heap Blocks", planstate->lossy_pages, es);
+ }
+ else
+ {
+ appendStringInfoSpaces(es->str, es->indent * 2);
+ appendStringInfoString(es->str, "Heap Blocks:");
+ if (planstate->exact_pages > 0)
+ appendStringInfo(es->str, " exact=%ld", planstate->exact_pages);
+ if (planstate->lossy_pages > 0)
+ appendStringInfo(es->str, " lossy=%ld", planstate->lossy_pages);
+ appendStringInfoChar(es->str, '\n');
+ }
+}
+
/*
* If it's EXPLAIN ANALYZE, show instrumentation information for a plan node
*
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 3d98c2335c1..1a8d4e51430 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -170,6 +170,11 @@ BitmapHeapNext(BitmapHeapScanState *node)
*/
bitgetpage(scan, tbmres);
+ if (tbmres->ntuples >= 0)
+ node->exact_pages++;
+ else
+ node->lossy_pages++;
+
/*
* Set rs_cindex to first slot to examine
*/
@@ -553,6 +558,8 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
scanstate->tbm = NULL;
scanstate->tbmiterator = NULL;
scanstate->tbmres = NULL;
+ scanstate->exact_pages = 0;
+ scanstate->lossy_pages = 0;
scanstate->prefetch_iterator = NULL;
scanstate->prefetch_pages = 0;
scanstate->prefetch_target = 0;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 94ab0f2a933..a301a08fba9 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1338,6 +1338,8 @@ typedef struct BitmapIndexScanState
* tbm bitmap obtained from child index scan(s)
* tbmiterator iterator for scanning current pages
* tbmres current-page data
+ * exact_pages total number of exact pages retrieved
+ * lossy_pages total number of lossy pages retrieved
* prefetch_iterator iterator for prefetching ahead of current page
* prefetch_pages # pages prefetch iterator is ahead of current
* prefetch_target target prefetch distance
@@ -1350,6 +1352,8 @@ typedef struct BitmapHeapScanState
TIDBitmap *tbm;
TBMIterator *tbmiterator;
TBMIterateResult *tbmres;
+ long exact_pages;
+ long lossy_pages;
TBMIterator *prefetch_iterator;
int prefetch_pages;
int prefetch_target;
--
GitLab