From: Matthew Schumacher <matt.s@aptalaska.net>
To: Andrew McMillan <andrew@catalyst.net.nz>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance problems testing with Spamassassin 3.1.0
Date: Fri, 29 Jul 2005 09:37:42 -0800
Message-ID: <42EA6966.8090402@aptalaska.net> (raw)
In-Reply-To: <1122616211.5691.340.camel@lamb.mcmillan.net.nz>
References: <42E80C28.2040608@aptalaska.net>
<1122532023.25574.1.camel@localhost.localdomain>
<42E9749F.6000709@aptalaska.net>
<1122616211.5691.340.camel@lamb.mcmillan.net.nz>
Andrew McMillan wrote:
> On Thu, 2005-07-28 at 16:13 -0800, Matthew Schumacher wrote:
>
>>Ok, I finally got some test data together so that others can test
>>without installing SA.
>>
>>The schema and test dataset is over at
>>http://www.aptalaska.net/~matt.s/bayes/bayesBenchmark.tar.gz
>>
>>I have a pretty fast machine with a tuned postgres and it takes it about
>>2 minutes 30 seconds to load the test data. Since the test data is the
>>bayes information on 616 spam messages than comes out to be about 250ms
>>per message. While that is doable, it does add quite a bit of overhead
>>to the email system.
>
>
> On my laptop this takes:
>
> real 1m33.758s
> user 0m4.285s
> sys 0m1.181s
>
> One interesting effect is the data in bayes_vars has a huge number of
> updates and needs vacuum _frequently_. After the run a vacuum full
> compacts it down from 461 pages to 1 page.
>
> Regards,
> Andrew.
>
I wonder why your laptop is so much faster. My 2 min 30 sec test was
done on a dual xeon with a LSI megaraid with 128MB cache and writeback
caching turned on.
Here are my memory settings:
shared_buffers = 16384
work_mem = 32768
maintenance_work_mem = 65536
I tried higher values before I came back to these but it didn't help my
performance any. I should also mention that this is a production
database server that was servicing other queries when I ran this test.
How often should this table be vacuumed, every 5 minutes?
Also, this test goes a bit faster with sync turned off, if mysql isn't
using sync that would be why it's so much faster. Anyone know what the
default for mysql is?
Thanks,
schu
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To: pgsql-performance@postgresql.org
Cc: matt.s@aptalaska.net, andrew@catalyst.net.nz
Subject: Re: Performance problems testing with Spamassassin 3.1.0
In-Reply-To: <42EA6966.8090402@aptalaska.net>
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