Re: constraint exclusion analysis caching

From: Stephen Frost <sfrost(at)snowman(dot)net>
To: Gregory Stark <stark(at)enterprisedb(dot)com>
Cc: Andrew Dunstan <andrew(at)dunslane(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: constraint exclusion analysis caching
Date: 2008-05-09 19:19:35
Message-ID: 20080509191935.GH5505@tamriel.snowman.net
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* Gregory Stark (stark(at)enterprisedb(dot)com) wrote:
> "Andrew Dunstan" <andrew(at)dunslane(dot)net> writes:
>
> > Actual execution of the query in question was talking one tenth of that
> > time.
> >...
> > but in principle it seems silly to keep paying the same penalty over and
> > over again.
>
> I would think constraint_exclusion only really makes sense if you're spending
> a lot more time executing than planning queries. Either that means you're
> preparing queries once and then executing them many many times or you're
> planning much slower queries where planning time is insignificant compared to
> the time to execute them.

Would it be possible to change the application to use prepared queries?
Seems like that'd make more sense the changing it to use the child
tables directly.. Just my 2c.

Thanks,

Stephen

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