Skip site navigation (1) Skip section navigation (2)

Re: wal_buffers, redux

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: wal_buffers, redux
Date: 2012-03-13 19:48:32
Message-ID: CA+TgmobSzuco2-P5NSuup879jinFPMOSZcuNENjK+JU86aAoCQ@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-hackers
On Mon, Mar 12, 2012 at 4:45 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
> Rerunning all 4 benchmarks (both 16MB and 32MB wal_buffers on both
> machines) with fsync=off (as well as synchronous_commit=off still)
> might help clarify things.

I reran the 32-client benchmark on the IBM machine with fsync=off and got this:

32MB: tps = 26809.442903 (including connections establishing)
16MB: tps = 26651.320145 (including connections establishing)

That's a speedup of nearly a factor of two, so clearly fsync-related
stalls are a big problem here, even with wal_buffers cranked up
through the ceiling.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

In response to

Responses

pgsql-hackers by date

Next:From: Kevin GrittnerDate: 2012-03-13 19:48:37
Subject: Re: pg_upgrade and statistics
Previous:From: Tom LaneDate: 2012-03-13 19:44:28
Subject: Re: pg_upgrade and statistics

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group