RE: How long are statistics good for
John My initial tests indicated that not all tables which had any DMLs were getting into the'stale category'. I checked the ratioA/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 theobjects with 'GATHER STALE' option. (But I get error for the partitioned tables with this option). Anand [EMAIL PROTECTED] 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: [EMAIL PROTECTED]Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051San Diego, California -- Public Internet access / Mailing ListsTo REMOVE yourself from this mailing list, send an E-Mail messageto: [EMAIL PROTECTED] (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).
How long are statistics good for
We have a data-warehouse that is a combination of Snapshots and table-builds based on the snapshots. The table builds run at 4:30 am, scripts are setup to start the snapshots at 7:00am and end at 9:00pm. At 6:30 am a script performs an analyze on ALL (except sys and system) tables in the database. If the snapshots have been running all day, should I run an analyze before I do the table builds? as opposed to after ? At what point do the statistics on a table become no good ? when a new row is added ? Thanks Darren -- Darren Browett P.EngThis message was transmitted Systems Analyst - Information Systems using 100% recycled electrons City of Coquitlam P:(604)927 - 3614 E:[EMAIL PROTECTED] --- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Browett, Darren INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists 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).
RE: How long are statistics good for
Statistics become old after a single change is made to the object. Granted adding a single row to a 1 Million row table isn't going to effect much. But adding 100,000 rows will. So where do you draw the line? I really don't know. But 5%-10% is generally a good measure. Sometimes more sometimes less depending on the size. Do not criticize someone until you walked a mile in their shoes, that way when you criticize them, you are a mile a way and have their shoes. Christopher R. Spence Oracle DBA Phone: (978) 322-5744 Fax:(707) 885-2275 Fuelspot 73 Princeton Street North, Chelmsford 01863 -Original Message- Sent: Tuesday, October 23, 2001 2:00 PM To: Multiple recipients of list ORACLE-L We have a data-warehouse that is a combination of Snapshots and table-builds based on the snapshots. The table builds run at 4:30 am, scripts are setup to start the snapshots at 7:00am and end at 9:00pm. At 6:30 am a script performs an analyze on ALL (except sys and system) tables in the database. If the snapshots have been running all day, should I run an analyze before I do the table builds? as opposed to after ? At what point do the statistics on a table become no good ? when a new row is added ? Thanks Darren -- Darren Browett P.EngThis message was transmitted Systems Analyst - Information Systems using 100% recycled electrons City of Coquitlam P:(604)927 - 3614 E:[EMAIL PROTECTED] --- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Browett, Darren INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists 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.com -- Author: Christopher Spence INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists 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).
Re: How long are statistics good for
Which version of Oracle are you using. In 8i you can set 'monitoring on' for the tables and use dbms_stats to analyze stale. (Though, I am getting error while using dbms_stats for the partitioned tables. So I have made a home made version to analyze stale). As per my calculations, package dbms_stats considers statistics stale ifall DMLsaffect more than 10% of number of rows. Anand Prakash [EMAIL PROTECTED] 10/23/01 11:00AM We have a data-warehouse that is a combination of Snapshots and table-buildsbased on the snapshots.The table builds run at 4:30 am, scripts are setup to start the snapshots at7:00am and end at 9:00pm. At 6:30 am a script performs an analyze on ALL (except sys andsystem) tables inthe database.If the snapshots have been running all day, should I run an analyze before Ido the table builds?as opposed to after ?At what point do the statistics on a table become no good ? when a new rowis added ?ThanksDarren--Darren Browett P.Eng This messagewas transmittedSystems Analyst - Information Systems using 100%recycled electrons City of Coquitlam P:(604)927 - 3614 E:[EMAIL PROTECTED] --- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com-- Author: Browett, Darren INET: [EMAIL PROTECTED]Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051San Diego, California -- Public Internet access / Mailing ListsTo REMOVE yourself from this mailing list, send an E-Mail messageto: [EMAIL PROTECTED] (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).
RE: How long are statistics good for
Anand, Just curious : Is there some test or other observation that you can share with the list about dbms_stats using 10% as a boundary for staleness? John Kanagaraj Which version of Oracle are you using. In 8i you can set 'monitoring on' for the tables and use dbms_stats to analyze stale. (Though, I am getting error while using dbms_stats for the partitioned tables. So I have made a home made version to analyze stale). As per my calculations, package dbms_stats considers statistics stale if all DMLs affect more than 10% of number of rows. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: John Kanagaraj INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists 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).
