From: David Rowley <drowley@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Widen lossy and exact page counters for Bitmap Heap Scan
Date: Mon, 08 Jul 2024 02:43:41 +0000
Message-ID: <E1sQeLt-000mlB-BZ@gemulon.postgresql.org> (raw)
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
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/7340d9362a792d3cb5f38a512d8cecacc7aceb59
Modified Files
--------------
src/backend/commands/explain.c | 12 ++++++------
src/include/nodes/execnodes.h | 4 ++--
2 files changed, 8 insertions(+), 8 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: drowley@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Widen lossy and exact page counters for Bitmap Heap Scan
In-Reply-To: <E1sQeLt-000mlB-BZ@gemulon.postgresql.org>
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