RE: SHOULD WE ANALYZE 9.2 SYS tables?

From: Lex de Haan <lex.de.haan_at_naturaljoin.nl>
Date: Thu, 29 Jul 2004 21:08:11 +0200
Message-ID: <JFEEIGBIDOCCDALDIPLNCEHLCGAA.lex.de.haan@naturaljoin.nl>

I must disagree here.
it is true that Oracle never actively encouraged customers to gather statistics for the SYS schema in Oracle9i, but it certainly cannot ruin your performance. Oracle also doesn't explicitly forbid you to gather DD statistics. you have to go back further in time (Oracle8i) to get into trouble with data dictionary statistics. I discussed this with the optimizer development team (when I was still inside Oracle) and they told me that there are no reasons at all *not* to gather statistics on the SYS schema. In other words, feel free.

as you probably know, various Oracle9i DD views actually have hints in their definitions, kicking in CBO anyway ...

Kind regards,
Lex.

visit my website at http://www.naturaljoin.nl

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Juan Carlos Reyes Pacheco
Sent: Thursday, July 29, 2004 19:42
To: oracle-l_at_freelists.org
Subject: Re: SHOULD WE ANALYZE 9.2 SYS tables?

Hi Larry
SYS schema don't need be analyzed, using tom kyte's word "it's magical" and must not be analyzed
if you got statistics in sys, you can ruin it's performance. sys schema don't have to be touched, this means don't create user tables in sys, etc.

Juan Carlos Reyes Pacheco
OCP
-------Original Message-------

From: oracle-l_at_freelists.org
Date: 07/29/04 14:25:41
To: 'oracle-l_at_freelists.org'
Subject: SHOULD WE ANALYZE 9.2 SYS tables?

I had a question about a problem with 9.2 V$ views where a RULE hint helped V$LOCK tremendously.

Someone suggested Analyzing the SYS tables. IS everyone doing that now or is there considerable reticence? I didn't get a much current information when I searched the FAQ or Google

Has anyone experienced a downside?

Is anyone doing some of the tables but not all?

Thanks
Larry Wolfson

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Received on Thu Jul 29 2004 - 14:05:00 CDT