Re: vacuum analyze hurts performance

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: aderose <aderose(at)tripology(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: vacuum analyze hurts performance
Date: 2008-09-03 15:17:51
Message-ID: 21160.1220455071@sss.pgh.pa.us
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aderose <aderose(at)tripology(dot)com> writes:
> Starting with a database where analyze has never been run I get worse
> performance after running it -- is there something I'm missing?

Well, not basing such a sweeping statement on a single query example
would be a good start ;-). This particular plan might have got a little
worse but I'm sure some further investigation would show other cases
that got better.

If you want to nudge it back towards the indexscan plan, reducing
random_page_cost a bit would probably do the trick. But that's
definitely not a parameter you want to adjust on the basis of only
one test case.

regards, tom lane

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