From 7340d9362a792d3cb5f38a512d8cecacc7aceb59 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Mon, 8 Jul 2024 14:43:09 +1200 Subject: [PATCH] Widen lossy and exact page counters for Bitmap Heap Scan Both of these counters were using the "long" data type. On MSVC that's a 32-bit type. On modern hardware, I was able to demonstrate that we can wrap those counters with a query that only takes 15 minutes to run. This issue may manifest itself either by not showing the values of the counters because they've wrapped and are less than zero, resulting in them being filtered by the > 0 checks in show_tidbitmap_info(), or bogus numbers being displayed which are modulus 2^32 of the actual number. Widen these counters to uint64. Discussion: https://postgr.es/m/CAApHDvpS_97TU+jWPc=T83WPp7vJa1dTw3mojEtAVEZOWh9bjQ@mail.gmail.com --- src/backend/commands/explain.c | 12 ++++++------ src/include/nodes/execnodes.h | 4 ++-- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 1e80fd8b68c..6defd26df50 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -3635,10 +3635,10 @@ show_tidbitmap_info(BitmapHeapScanState *planstate, ExplainState *es) { if (es->format != EXPLAIN_FORMAT_TEXT) { - ExplainPropertyInteger("Exact Heap Blocks", NULL, - planstate->exact_pages, es); - ExplainPropertyInteger("Lossy Heap Blocks", NULL, - planstate->lossy_pages, es); + ExplainPropertyUInteger("Exact Heap Blocks", NULL, + planstate->exact_pages, es); + ExplainPropertyUInteger("Lossy Heap Blocks", NULL, + planstate->lossy_pages, es); } else { @@ -3647,9 +3647,9 @@ show_tidbitmap_info(BitmapHeapScanState *planstate, ExplainState *es) ExplainIndentText(es); appendStringInfoString(es->str, "Heap Blocks:"); if (planstate->exact_pages > 0) - appendStringInfo(es->str, " exact=%ld", planstate->exact_pages); + appendStringInfo(es->str, " exact=" UINT64_FORMAT, planstate->exact_pages); if (planstate->lossy_pages > 0) - appendStringInfo(es->str, " lossy=%ld", planstate->lossy_pages); + appendStringInfo(es->str, " lossy=" UINT64_FORMAT, planstate->lossy_pages); appendStringInfoChar(es->str, '\n'); } } diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index b62c96f2064..abfcd5f5905 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1817,8 +1817,8 @@ typedef struct BitmapHeapScanState TBMIterator *tbmiterator; TBMIterateResult *tbmres; Buffer pvmbuffer; - long exact_pages; - long lossy_pages; + uint64 exact_pages; + uint64 lossy_pages; TBMIterator *prefetch_iterator; int prefetch_pages; int prefetch_target;