Re: Optimizer improvements: to do or not to do? - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: Optimizer improvements: to do or not to do?
Date
Msg-id 200609131004.54060.peter_e@gmx.net
Whole thread Raw
In response to Re: Optimizer improvements: to do or not to do?  ("Say42" <andrews42@yandex.ru>)
Responses Re: Optimizer improvements: to do or not to do?  ("Say42" <andrews42@yandex.ru>)
List pgsql-hackers
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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