Re: Optimizer improvements: to do or not to do?

From: Peter Eisentraut <peter_e(at)gmx(dot)net>
To: pgsql-hackers(at)postgresql(dot)org
Cc: "Say42" <andrews42(at)yandex(dot)ru>
Subject: Re: Optimizer improvements: to do or not to do?
Date: 2006-09-13 08:04:53
Message-ID: 200609131004.54060.peter_e@gmx.net
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Say42 wrote:
> Perhaps I am wrong but I assume normalization is a usual case, small
> master (parent) tables are not very rare also.
> Yes, my example is unusual but it is _real_ and demonstrate PG
> optimizer inaccuracy. Why don't we make PG optimizer more close to
> reality if we can? Is it so needless and I make a mountain out of a
> molehill?

All you have shown so far is that one particular query runs faster on
your machine when sequential scans are turned off. That is certainly a
problem that is worth addressing. But you haven't offered any analysis
about the cause of this problem, so any speculation about
normalization, usual cases, caching effects and so on are unfounded and
premature.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

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