Re: Query 4-5 times slower after ANALYZE

hi

it's look better with explain.depesz.com :) you can easily find that
in "before" it uses index scan and in "after" it uses seq


before:

http://explain.depesz.com/s/RC

after:

http://explain.depesz.com/s/nm

try as mentioned before to change costs

Best regards,

Sebastian Pawłowski


Wiadomość napisana w dniu 2009-03-18, o godz. 10:55, przez Philippe
Lang:

> Hi,
>
> I'm using Postgresql 8.3.6 under Freebsd 7.1.
>
> After a fresh restore of a customer dump (running version 8.2.7 at the
> moment), a rather big query executes in about 30 seconds. As soon as I
> run ANALYZE, it is instantly 4-5 times slower. I could check that
> multiples times.
>
> Here is the EXPLAIN ANALYZE before the ANALYZE:
> http://www.attiksystem.ch/postgresql/query_slower_after_analyze/before.t
> xt
>
> And here the the EXPLAIN ANALYZE after the ANALYZE:
> http://www.attiksystem.ch/postgresql/query_slower_after_analyze/after.tx
> t
>
> Any idea what could be turned on/off in order not to have this
> slowdown
> after the ANALYZE?
>
> Best regards,
>
> ---------------
> Philippe Lang
> Attik Syste,
>
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