pgsql: Fix EXPLAIN Bitmap heap scan to count pages with no visible tupl - Mailing list pgsql-committers

Fix EXPLAIN Bitmap heap scan to count pages with no visible tuples

Previously, bitmap heap scans only counted lossy and exact pages for
explain when there was at least one visible tuple on the page.

heapam_scan_bitmap_next_block() returned true only if there was a
"valid" page with tuples to be processed. However, the lossy and exact
page counters in EXPLAIN should count the number of pages represented
in a lossy or non-lossy way in the constructed bitmap, regardless of
whether or not the pages ultimately contained visible tuples.

Backpatch to all supported versions.

Author: Melanie Plageman
Discussion: https://www.postgresql.org/message-id/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA@mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAAKRu_bxrXeZ2rCnY8LyeC2Ls88KpjWrQ%2BopUrXDRXdcfwFZGA@mail.gmail.com

Branch
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REL_16_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/1f4eb734200a2420f45d0204d95b65ddf707888c

Modified Files
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src/backend/executor/nodeBitmapHeapscan.c     | 10 +++++-----
src/test/regress/expected/partition_prune.out |  4 +++-
2 files changed, 8 insertions(+), 6 deletions(-)