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Re: Bug? 8.0 does not use partial index

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Palle Girgensohn <girgen(at)pingpong(dot)net>
Cc: John Hansen <john(at)geeknet(dot)com(dot)au>, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: Bug? 8.0 does not use partial index
Date: 2005-01-14 04:01:12
Message-ID: 19367.1105675272@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
Palle Girgensohn <girgen(at)pingpong(dot)net> writes:
>> No surprise.  vacuum analyze produces an exact total row count, whereas
>> analyze can only produce an approximate total row count (since it only
>> samples the table rather than groveling over every row).  Sometimes the
>> approximate count will be far enough off to affect the estimates.

> Reasonable. Thanks for clarifying that. In the normal case, vacuum analyze 
> is better, I guess?

If you intend to do both steps, the combined command is definitely
better than issuing them separately.  I wouldn't say that you need to
do the combined command in situations where you'd otherwise do just
one.

			regards, tom lane

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