From AnandPrakash@firsthealth.com Wed, 24 Oct 2001 08:29:35 -0700 From: "Anand Prakash" Date: Wed, 24 Oct 2001 08:29:35 -0700 Subject: RE: How long are statistics good for Message-ID: MIME-Version: 1.0 Content-Type: text/plain John   My initial tests indicated that not all tables which had any DMLs were getting into the 'stale category'. I checked the ratio A/B where: A is the sum of inserts+deletes+updates from user_tab_modifications B is num_rows from user_tables (or user_tab_partitions).   I observed that if this ratio exceeded 10%, package dbms_stats analyzed the objects with 'GATHER STALE' option. (But I get error for the partitioned tables with this option).   Anand      >>> john.kanagaraj@hds.com 10/23/01 05:20PM >>>Anand,Just curious : Is there some test or other observation that you can sharewith the list about dbms_stats using 10% as a boundary for staleness?John KanagarajWhich version of Oracle are you using. In 8i you can set 'monitoring on' forthe tables and use dbms_stats to analyze stale. (Though, I am getting errorwhile using dbms_stats for the partitioned tables. So I have made a homemade version to analyze stale). As per my calculations, package dbms_statsconsiders statistics stale if all DMLs affect more than 10% of number ofrows.-- Please see the official ORACLE-L FAQ: http://www.orafaq.com-- Author: John Kanagaraj  INET: john.kanagaraj@hds.comFat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051San Diego, California        -- Public Internet access / Mailing Lists--------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail messageto: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and inthe message BODY, include a line containing: UNSUB ORACLE-L(or the name of mailing list you want to be removed from).  You mayalso send the HELP command for other information (like subscribing).