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Re: Estimate versus Compute

From: Connor McDonald <mcdonald.connor_at_gmail.com>
Date: Tue, 26 Jul 2005 09:06:17 +0800
Message-ID: <5e304862050725180658a52aea@mail.gmail.com>


I'm not a great fan of auto-sample-size because

  1. it does more work
  2. last time I checked, it can be fooled

http://www.oracledba.co.uk/tips/9i_dbms_stats.htm

I'm generally more inclined just to take segment size to determine an dbms_stats estimate size - it naturally doesn't cover segments that have grown and shrunk over time, but its not as if its being run all the time anyway

hth
connor

On 7/26/05, Allen, Brandon <Brandon.Allen_at_oneneck.com> wrote:
> The database with the results I mentioned earlier is version 8.0.6, so I'm using dbms_utility (dbms_stats didn't exist yet).
>
> I switched from this:
>
> EXECUTE dbms_utility.analyze_schema('BAAN','COMPUTE');
>
> To this:
>
> EXECUTE dbms_utility.analyze_schema(schema=>'BAAN',method=>'ESTIMATE',estimate_percent=>25,method_opt=>'FOR TABLE');
> EXECUTE dbms_utility.analyze_schema(schema=>'BAAN',method=>'COMPUTE',method_opt=>'FOR ALL INDEXES');
>

-- 
Connor McDonald
===========================
email: connor_mcdonald_at_yahoo.com
web:   http://www.oracledba.co.uk

"Semper in excremento, sole profundum qui variat"
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Received on Mon Jul 25 2005 - 20:08:15 CDT

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