From: Csaba Nagy <nagy@ecircle-ag.com>
To: Andrew Sullivan <ajs@crankycanuck.ca>
Cc: postgres performance list <pgsql-performance@postgresql.org>
Subject: Re: Help tuning postgres
Date: Thu, 13 Oct 2005 10:15:03 +0200
Message-ID: <1129191303.2995.192.camel@coppola.muc.ecircle.de> (raw)
In-Reply-To: <20051012220036.GE13571@phlogiston.dyndns.org>
References: <1129128315.2995.174.camel@coppola.muc.ecircle.de>
<f3c0b4080510120939x6c08feebvfad37c98df306538@mail.gmail.com>
<1129136130.2995.188.camel@coppola.muc.ecircle.de>
<20051012220036.GE13571@phlogiston.dyndns.org>
[snip]
> Yes, but it could be a disk issue because you're doing more work than
> you need to. If your UPDATEs are chasing down a lot of dead tuples,
> for instance, you'll peg your I/O even though you ought to have I/O
> to burn.
OK, this sounds interesting, but I don't understand: why would an update
"chase down a lot of dead tuples" ? Should I read up on some docs, cause
I obviously don't know enough about how updates work on postgres...
And how would the analyze help in finding this out ? I thought it would
only show me additionally the actual timings, not more detail in what
was done...
Thanks,
Csaba.
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To: pgsql-performance@postgresql.org
Cc: nagy@ecircle-ag.com, ajs@crankycanuck.ca
Subject: Re: Help tuning postgres
In-Reply-To: <1129191303.2995.192.camel@coppola.muc.ecircle.de>
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