Re: Query performance. 7.2.3 Vs. 7.3

From: wade <wade(at)wavefire(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Query performance. 7.2.3 Vs. 7.3
Date: 2002-11-29 16:36:10
Message-ID: 3.0.32.20021129083610.01605dc0@mail.wavefire.com
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At 09:58 PM 11/28/02 -0500, you wrote:
>Hm. Are we sure that both versions were built with the same
>optimization level, etc? (My private bet is that Wade's 7.2 didn't
>have multibyte or locale support --- but that's a long shot when we
>don't know the datatypes of the columns being joined on...)
>
>> Also, is it expected that the cardinality estimates for join steps won't
>> be very accurate, right? (estimated: 19 rows, actual: 765 rows)
OK, I've updated the link http://arch.wavefire.com/72v73a.txt to include
the table schema for those involved in the query. As far as locale suport
et al, I can tell you that both are built using a straigh, out-of-the-box
./configure.
>
>Well, it'd be nice to do better --- I was hoping Wade would look into
>why the row estimates were off so much.
I'd love to :). But where to start? Can you point me at a thread where a
similar procedure was explained to someone else?
-Wade
>
> regards, tom lane
>
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