Raj: Wolfgang is right. It is populated by SMON (I think every 15mins SMON flushes the data to COL_USAGE) and the predicate columns are updated (or collected) from the hard parse of the SQLs.
Best Regards, K Gopalakrishnan -----Original Message----- Wolfgang Breitling Sent: Tuesday, November 18, 2003 8:59 AM To: Multiple recipients of list ORACLE-L That is a new table in Oracle 9 and is used by Oracle to track what columns are used in predicates. At present the only use of that information that I am aware of is in the procedure dbms_stats.gather_table_stats ( ..., method_opt => 'for columns ... size auto'); At 09:29 AM 11/18/2003, you wrote: >Does anyone know what this table (sys.col_usage$) is used for? To me it >sounds like something that CBO might appreciate ... but any ideas? It is >referenced by dbms_stats and dbms_stats_internal packages ... > >Thanks in advance >Raj >--------------------------------------------------------------------------- ----- > >Rajendra dot Jamadagni at nospamespn dot com Wolfgang Breitling Oracle7, 8, 8i, 9i OCP DBA Centrex Consulting Corporation http://www.centrexcc.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Wolfgang Breitling INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: K Gopalakrishnan INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
