Re: [HACKERS] Re: Top N queries and disbursion

From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Roberto Cornacchia <rcorna(at)tin(dot)it>, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] Re: Top N queries and disbursion
Date: 1999-10-08 16:33:36
Message-ID: 199910081633.MAA28027@candle.pha.pa.us
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> I don't have a better idea right at the moment. I'm open to the idea
> that VACUUM should compute more or different statistics, though ---
> as long as it doesn't slow things down too much. (How much is too much
> would probably depend on how much win the new stats would provide for
> normal query-planning. For example, I'd resist making two passes over
> the table during VACUUM ANALYZE, but I wouldn't rule it out completely;
> you could sell me on it if the advantages were great enough.)
>
> Hey, you guys are the researchers ... give us a better approach to
> keeping table statistics ;-)

Yes, I am open to better ideas. The current code does 2-value columns,
and unique columns perfectly. The other distributions it gets only
approximate answers, but for a one-pass system, that's the best I could
do.

--
Bruce Momjian | http://www.op.net/~candle
maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026

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