Re: [ADMIN] shared_buffers and shmmax

I have added this TODO item:

Rationalize the discrepancy between settings that use values in bytes
and SHOW that returns the object count

* http://archives.postgresql.org/pgsql-docs/2008-07/msg00007.php

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Greg Sabino Mullane wrote:
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> >> shared_buffers is in disk block size, typically 8K
>
> > The table the OP is looking at (table 17.2 in the 8.3 docs) predates
> > the ability to specify shared_buffers in KB or MB instead of
> > number-of-buffers. I agree it's not entirely obvious that what it
> > means is "multiply your setting in KB/MB by 8400/8192". Anybody have
> > an idea how to clarify things?
>
> Bite the bullet and start showing the buffer settings as a pure number of bytes
> everywhere, and get rid of the confusing '8kB' unit in pg_settings? Things like
> this don't help our cause:
>
> test=# show shared_buffers;
> shared_buffers
> ----------------
> 24MB
> (1 row)
>
> test=# set temp_buffers = '24MB';
> SET
>
> test=# show temp_buffers;
> temp_buffers
> --------------
> 3072
>
> test=# select name, setting from pg_settings where name ~ 'buffers';
> name | setting
> ----------------+---------
> shared_buffers | 3072
> temp_buffers | 3072
> wal_buffers | 8
>
> test=# show wal_buffers;
> wal_buffers
> -------------
> 64kB
>
>
> --
> Greg Sabino Mullane greg(at)turnstep(dot)com
> End Point Corporation
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--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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