From: Jerry Sievers <gsievers19@comcast.net>
To: Bob Jolliffe <bobjolliffe@gmail.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Interpreting shared_buffers setting
Date: Tue, 29 Jan 2019 12:31:51 -0600
Message-ID: <87k1in9uy0.fsf@jsievers.enova.com> (raw)
In-Reply-To: <CACd=f9f1ODAgnEsUagdfyChEXsE4OD5V3LyXvuUozquZUgYo9A@mail.gmail.com>
References: <CACd=f9f1ODAgnEsUagdfyChEXsE4OD5V3LyXvuUozquZUgYo9A@mail.gmail.com>
Bob Jolliffe <bobjolliffe@gmail.com> writes:
> Excuse me if this is a silly question. I am trying to fiddle with
> shared_buffers setting on postgresql 10.6 on ubuntu 18.04 server.
>
> I have this at bottom of my config file:
> shared_buffers = 1GB
>
> Yet when I check the setting from pg_setting I see something quite different:
>
> postgres=# SELECT name, setting FROM pg_settings where name = 'shared_buffers';
> name | setting
> ----------------+---------
> shared_buffers | 131072
Why not use the show command which is good about output in human
terms...
psql (11.1 (Ubuntu 11.1-1.pgdg16.04+1))
Type "help" for help.
meta_a:postgres# select name, setting from pg_settings where name = 'shared_buffers');
ERROR: syntax error at or near ")"
LINE 1: ...me, setting from pg_settings where name = 'shared_buffers');
^
meta_a:postgres#
>
> Is this a question of units? It looks like 128M. Note when I change
> the setting to 2GB in conf file I see 262144 from pg_setting. I am
> now unsure what the actual shared_buffers allocation is. I cant see
> anything in the docs which tells me how to interpret the integer.
>
> Any clarification welcome.
>
> Regards
> Bob
>
>
--
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consulting@comcast.net
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To: pgsql-performance@postgresql.org
Cc: gsievers19@comcast.net, bobjolliffe@gmail.com, pgsql-performance@lists.postgresql.org
Subject: Re: Interpreting shared_buffers setting
In-Reply-To: <87k1in9uy0.fsf@jsievers.enova.com>
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