Re: Data and logs on different physical drives - advantage? - Mailing list pgsql-admin

From Tom Lane
Subject Re: Data and logs on different physical drives - advantage?
Date
Msg-id 20615.1128954890@sss.pgh.pa.us
Whole thread Raw
In response to Data and logs on different physical drives - advantage?  ("Weber, Johann (ISS Kassel)" <jweber@iss.net>)
List pgsql-admin
"Weber, Johann (ISS Kassel)" <jweber@iss.net> writes:
> Is this true for PostgreSQL (V 8.0 on ReadHat)? My tests do not show any
> speed gained when placing pg_clog and pg_xlog on a different drive.

The conventional wisdom is that it's a win to have pg_xlog on a drive by
itself.  The above is not that.  pg_clog is more in the nature of data,
and in any case you lose the advantage as soon as the drive handling
pg_xlog has to move the head away from the current xlog file.

Whether any particular test case would show an advantage is another
question of course.  In a heavy-write scenario I would think you could
probably measure a win.

            regards, tom lane

pgsql-admin by date:

Previous
From: Tom Lane
Date:
Subject: Re: Update - pg_dumpall money problem
Next
From: "Weber, Johann (ISS Kassel)"
Date:
Subject: Re: Data and logs on different physical drives - advantage?