From: Andres Freund <andres@anarazel.de>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Don't initialize page in {vm,fsm}_extend(), not needed
Date: Wed, 05 Apr 2023 16:21:46 +0000
Message-ID: <E1pk5tJ-001W2q-Bq@gemulon.postgresql.org> (raw)
Don't initialize page in {vm,fsm}_extend(), not needed
The read path needs to be able to initialize pages anyway, as relation
extensions are not durable. By avoiding initializing pages, we can, in a
future patch, extend the relation by multiple blocks at once.
Using smgrextend() for {vm,fsm}_extend() is not a good idea in general, as at
least one page of the VM/FSM will be read immediately after, always causing a
cache miss, requiring us to read content we just wrote.
Discussion: https://postgr.es/m/20230301223515.pucbj7nb54n4i4nv@awork3.anarazel.de
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/3d6a98457d8e21d85bed86cfd3e1d1df1b260721
Modified Files
--------------
src/backend/access/heap/visibilitymap.c | 6 +-----
src/backend/storage/freespace/freespace.c | 5 +----
2 files changed, 2 insertions(+), 9 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: andres@anarazel.de, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Don't initialize page in {vm,fsm}_extend(), not needed
In-Reply-To: <E1pk5tJ-001W2q-Bq@gemulon.postgresql.org>
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