Make bitmap heap scans show exact/lossy block info in EXPLAIN ANALYZE.

Etsuro Fujita

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 7097eff9b114522b74b49816592b0933efaa28da..e604be31f9d741dc39835bd7c1526419d8034220 100644 (file)
--- 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 3d98c2335c17239b65fdba1d34b3ba0ebf7cba6c..1a8d4e51430b232d96080da14a3ecd781f2787d0 100644 (file)
--- 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 94ab0f2a93368dda4f3bf144a28a0bca20b317d9..a301a08fba9f1c532ce58a8ea8f2c7ea11511001 100644 (file)
--- 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;