RE: Analyze vs. DBMS

From: Toepke, Kevin M <ktoepke_at_trilegiant.com>
Date: Thu, 10 Jan 2002 08:25:52 -0800
Message-ID: <F001.003EC6BA.20020110075535@fatcity.com>

I would highly recommend that you move to DBMS_STATS if you are running at least 8.1.6.3 -- especially if you are estimating statistics.

The reason is that DBMS_STATS generates more and better statistics than analyze. I've seen queries go from hours to minutes just by changing from ANALYZE to DBMS_STATS...

There are a couple situations where you don't want to use DBMS_STATS -- when you are using partitioned function-based indexes. DBMS_STATS doesn't seem to do right. Just another issue with function-based indexes that is supposed to be fixed in 9.0.2.

Caver

-----Original Message-----
Sent: Thursday, January 10, 2002 10:31 AM To: Multiple recipients of list ORACLE-L

Now that I finally have all of our databases upgraded to 8.1.7 I am taking some time to look at our method of gathering statistics for CBO. It looks like I should move towards using DBMS_STATS to gather statistics, but I may want to use ANALYZE if I need to gather stats on individual columns (according to Note:166215.1). I was just curious to know if most DBAs are using DBMS_STATS instead of ANALYZE. For the most part, I had been using DBMS_UTILITY.ANALYZE_SCHEMA. I'll probably start using DBMS_STATS.GATHER_SCHEMA_STATS unless somebody convinces me otherwise. Any comments or things that I should watch out for?

Thanks,

Jay Hostetter
Oracle DBA
D. & E. Communications
Ephrata, PA USA

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Author: Jay Hostetter
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Author: Toepke, Kevin M
INET: ktoepke_at_trilegiant.com

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RE: Analyze vs. DBMS_STATS