Few questions about statistics

From: <Uldis.Pavuls_at_tietoenator.com>
Date: Tue, 15 Apr 2008 18:36:15 +0300
Message-ID: <4ED1B8DD6EC2434E85A5E11ABD7D160601250C12@sagaris.eu.tieto.com>

Hi All

In general I know the difference between ANALYZE units in DBMS_UTILITY and ones in DBMS_STATS. What I lack, it's a couple of details (particularly in 9.2 if it makes a difference):
- Which exactly are the optimizer statistics (and which isn't)? Because
it's said that DBMS_UTILITY don't gather all what's necessary for CBO, while, on the other hand, DBMS_STATS don't bother with stats not needed for CBO.
- How can I know when the last time ANALYZE from DBMS_UTILITY had been
run on the object and when a unit from DBMS_STATS (e.g. DBMS_STATS.GATHER_TABLE_STATS) had? (They both update dictionary, e.g. DBA_TABLES.LAST_ANALYZED). In fact this is a question whether the CBO sats are up to date and valid.

Uldis Pavuls

Received on Tue Apr 15 2008 - 10:36:15 CDT

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