Re: [HACKERS] Some notes on optimizer cost estimates - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Some notes on optimizer cost estimates
Date
Msg-id 26758.948421841@sss.pgh.pa.us
Whole thread Raw
In response to RE: [HACKERS] Some notes on optimizer cost estimates  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
Responses Re: [HACKERS] Some notes on optimizer cost estimates
RE: [HACKERS] Some notes on optimizer cost estimates
List pgsql-hackers
"Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
> I've wondered why we cound't analyze database without vacuum.
> We couldn't run vacuum light-heartedly because it acquires an
> exclusive lock for the target table. 

There is probably no real good reason, except backwards compatibility,
why the ANALYZE function (obtaining pg_statistic data) is part of
VACUUM at all --- it could just as easily be a separate command that
would only use read access on the database.  Bruce is thinking about
restructuring VACUUM, so maybe now is a good time to think about
splitting out the ANALYZE code too.

> In addition,vacuum error occurs with analyze option in most
> cases AFAIK. 

Still, with current sources?  What's the error message?  I fixed
a problem with pg_statistic tuples getting too big...
        regards, tom lane


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