RE: CBO Question - Is 'monitoring' used to calculate query plan?
- From: "Mercadante, Thomas F (LABOR)" <Thomas.Mercadante@xxxxxxxxxxxxxxxxx>
- To: <jkstill@xxxxxxxxx>, "Oracle-L Freelists" <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 8 Jan 2009 14:58:58 -0500
Jared,
In the 10.2. docs:
file:///V:/Oracle10.2Doc/B19306_01/server.102/b14200/statements_7002.htm
#i2095331
<file:///\\dol0a1fs1\P&t\database\Oracle10.2Doc\B19306_01\server.102\b14
200\statements_7002.htm#i2095331>
Tom
MONITORING | NOMONITORING
In earlier releases, you could use these clauses to start or stop the
collection of modification statistics on this table. These clauses have
been deprecated.
* If you formerly collected modification statistics on tables by
using the DBMS_STATS package in GATHER AUTO or GATHER STALE mode, then
you no longer have to do anything. Oracle Database now collects these
statistics automatically, and the MONITORING and NOMONITORING keywords
in existing code will not cause an error.
* If, for performance reasons, you do not want to collect
modification statistics on any tables, then you should set the
STATISTICS_LEVEL initialization parameter to BASIC. Be aware, however,
that doing so disables a number of manageability features.
See Also:
Oracle Database Reference for information on the STATISTICS_LEVEL
<file:///V:\Oracle%2010.2%20Doc\B19306_01\server.102\b14237\initparams21
0.htm#REFRN10214> initialization parameter, including its affect on
Oracle Database manageability features
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Jared Still
Sent: Thursday, January 08, 2009 2:53 PM
To: Oracle-L Freelists
Subject: CBO Question - Is 'monitoring' used to calculate query plan?
From the 9i SQL manual:
MONITORING Clause
Specify MONITORING if you want Oracle to collect modification statistics
on table. These statistics are estimates of the number of rows affected
by DML statements over a particular period of time. They are available
for use by the optimizer or for analysis by the user.
I can't find such a reference for 10g or 11g.
Does anyone know definitively if that is still the case for newer
versions of Oracle?
A link to such documentation would be useful if you have it handy.
Thanks,
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist
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