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Re: What's your opinion: ALL_ROWS vs FIRST_ROWS

From: Tom Pall <tpall_at_realtime.net>
Date: Wed, 30 Oct 2002 10:00:09 -0800
Message-ID: <F001.004F7B0C.20021030100009@fatcity.com>


I guess that's why when I take a look at the initialization files of databases in large shops where it's expected the DBAs know what they're doing, by and large the databases are running in CHOOSE (all rows if there are sufficient statistics) mode.
----- Original Message -----
To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: Wednesday, October 30, 2002 11:19 AM

> We have an OLTP system that I thought will benefit from first rows.
> The sad fact is that when I set optimization to first rows the response
> sucks.
>
> Do some testing, as you can change this anytime.
>
> Yechiel Adar
> Mehish
> ----- Original Message -----
> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> Sent: Tuesday, October 29, 2002 11:13 PM
>
>
> > We're moving from RBO to CBO.
> >
> > For those of you who use CBO, what mode do you use FIRST_ROWS or
ALL_ROWS?
> > And why?
> >
> > My thinking is if it's a database where most of the querying is done on
> > small sets of records, then we may want to use FIRST_ROWS. On the other
> > hand, if our database is used to generate sizable reports, we might use
> > ALL_ROWS.
> >
> > I also understand that we can always change it per session (with alter
> > session) and per query (with hints).
> >
> > Michael Armstead
> > Principal Database Administrator, OCP-Certified
> > World Wide Corporate IT Database Administration
> > GlaxoSmithKline
> >
> >
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > --
> > Author: Armstead, Michael A
> > INET: maa25681_at_GlaxoWellcome.com
> >
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> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Yechiel Adar
> INET: adar76_at_inter.net.il
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Tom Pall
  INET: tpall_at_realtime.net

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
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Received on Wed Oct 30 2002 - 12:00:09 CST

Original text of this message

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