Re: raising the default default_statistics_target - Mailing list pgsql-hackers

From Tom Lane
Subject Re: raising the default default_statistics_target
Date
Msg-id 23289.1078700399@sss.pgh.pa.us
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In response to raising the default default_statistics_target  (Neil Conway <neilc@samurai.com>)
Responses Re: raising the default default_statistics_target  (Neil Conway <neilc@samurai.com>)
List pgsql-hackers
Neil Conway <neilc@samurai.com> writes:
> Any comments on whether increasing the default stats target is a good 
> idea for 7.5? (Details on the test I performed are included below)

This is something we need to consider, but we'll need more evidence
before making a choice.  One thing that we have very little data about
is how much difference it makes in the quality of planner choices.
(There's no point in slowing down ANALYZE unless the plans get better.)

Also, I would expect that larger stats targets would slow down the parts
of the planner that look at the stats, since there are more data values
to examine.  I do not have any numbers about this cost though --- do you
want to try to get some?
        regards, tom lane


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