From: Michael Paquier <michael@paquier.xyz>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: bloom: Optimize bitmap scan path with streaming read
Date: Tue, 10 Mar 2026 22:36:27 +0000
Message-ID: <E1w05gh-003NMc-32@gemulon.postgresql.org> (raw)
bloom: Optimize bitmap scan path with streaming read
This commit replaces the per-page buffer read look in blgetbitmap() with
a reading stream, to improve scan efficiency, particularly useful for
large bloom indexes. Some benchmarking with a large number of rows has
shown a very nice improvement in terms of runtime and IO read reduction
with test cases up to 10M rows for a bloom index scan.
For the io_uring method, The author has reported a 3x in runtime with
io_uring while I was at close to a 7x. For the worker method with 3
workers, the author has reported better numbers than myself in runtime,
with the reduction in IO stats being appealing for all the cases
measured.
Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CABPTF7VrqfbcDXqGrdLQ2xaQ=K0RzExNuw6U_GGqzSJu32wfdQ@mail.gmail.com
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/4c910f3bbe92aa4e84ff15fa27b4de2da0d7ae50
Modified Files
--------------
contrib/bloom/blscan.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: michael@paquier.xyz, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: bloom: Optimize bitmap scan path with streaming read
In-Reply-To: <E1w05gh-003NMc-32@gemulon.postgresql.org>
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