From: Worky Workerson <worky.workerson@gmail.com>
To: Jim C. Nasby <jim@nasby.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Best COPY Performance
Date: Tue, 31 Oct 2006 16:22:11 -0400
Message-ID: <ce4072df0610311222l2d3edf91uf15119c53fe886d5@mail.gmail.com> (raw)
In-Reply-To: <20061026033448.GC26892@nasby.net>
References: <ce4072df0610201305u7836dc7bn437ec0aaf1c3e25f@mail.gmail.com>
<453C8B0D.4070803@logix-tt.com>
<ce4072df0610230840r4b3df653h3144dab06bdb9ed2@mail.gmail.com>
<b42b73150610250620r37cf9269m7b6e43b9835bdbcf@mail.gmail.com>
<ce4072df0610250825h324d30datece27c0c541162ff@mail.gmail.com>
<20061026033448.GC26892@nasby.net>
> >I'm guessing the high bursts are checkpoints. Can you check your log
> > >files for pg and see if you are getting warnings about checkpoint
> > >frequency? You can get some mileage here by increasing wal files.
> >
> > Nope, nothing in the log. I have set:
> > wal_buffers=128
> > checkpoint_segments=128
> > checkpoint_timeout=3000
> > which I thought was rather generous. Perhaps I should set it even
> > higher for the loads?
>
> But depending on your shared_buffer and bgwriter settings (as well as
> how much WAL traffic you're generating, you could still end up with big
> slugs of work to be done when checkpoints happen.
>
> If you set checkpoint_warning to 3001, you'll see exactly when
> checkpoints are happening, so you can determine if that's an issue.
I did that, and I get two log messages, seeing checkpoints happening
at 316 and 147 seconds apart on my load of a 1.9 GB file. Is this "an
issue"?
Thanks!
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To: pgsql-performance@postgresql.org
Cc: worky.workerson@gmail.com, jim@nasby.net
Subject: Re: Best COPY Performance
In-Reply-To: <ce4072df0610311222l2d3edf91uf15119c53fe886d5@mail.gmail.com>
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