In the docs I've just checked for 9.2 Oracle recommends that log_checkpoint_timeout, log_checkpoint_interval and fast_start_io_target are all set to 0 if you're using fast_start_mtr_target because (as the tuning manual says) "..setting these parameters to active values interferes with FAST_START_MTTR_TARGET, resulting in a different than expected value V$INSTANCE_RECOVERY.TARGET_MTTR".
The reference manual states that FAST_START_MTTR_TARGET is overridden (when specified) by FAST_START_IO_TARGET and LOG_CHECKPOINT_INTERVAL. I've been playing with this a little on 9.2. If you have log_checkpoint_interval unset then altering the value of fast_start_mttr_target influences the value of V$INSTANCE_RECOVERY.MTTR_TARGET. However when you set log_checkpoint_interval the value of fast_start_mttr_target seems to become less important. Hardly conclusive yet but certainly if I wanted to use fast_start_mttr_target I wouldn't be setting the related parameters. And anyway, what effect does this have on _spin_count? Regards, Mike Hately -----Original Message----- Sent: 20 November 2002 15:24 To: Multiple recipients of list ORACLE-L log_checkpoint_inte Gillian - I love it! Dueling Instructors! Since you are still in class, why don't you show him the manual and ask for clarification. Please check the class notes on this. My copy is at home. Thanks. Dennis Williams DBA, 40%OCP Lifetouch, Inc. [EMAIL PROTECTED] -----Original Message----- Sent: Tuesday, November 19, 2002 5:10 PM To: Multiple recipients of list ORACLE-L ok - it so happens I am in the middle of the 9i New Features class. I just clarified that with the instuctor. And he repeated that if the log_checkpotint parameters are set, as well as the MTTR, then MTTR overides whatever the log_checkpoint parameters are set to. I did not check out the official documentation. But the class manual says, 'Internally this is translated to a setting for Log_checkpoint_interval' The instructor's name is Steve Bertuoi. Not sure how good he knows his stuff. I guess I could play around with their test database here in the class, and see what really happens. Gillian DENNIS WILLIAMS <[EMAIL PROTECTED]> wrote: Gillian - But the documentation clearly says just the opposite. It says that if you set the LOG_CHECKPOINT_INTERVAL parameter, then that is what is used, rather than FAST_START_MTTR_TARGET. So I don't see how you can say that FAST_START_MTTR_TARGET overrides the LOG_CHECKPOINT_INTERVAL. Am I missing something here? Dennis Williams DBA, 40%OCP Lifetouch, Inc. [EMAIL PROTECTED] -----Original Message----- Sent: Tuesday, November 19, 2002 12:59 PM To: Multiple recipients of list ORACLE-L Just to add: The MTTR parameter overides the Log_checkpoint_interval and the ...timeout parameter. Oracle sets these log_checkpoint parameters dynamically when the MTTR parameter is set. Gillian DENNIS WILLIAMS wrote: Dist - Since nobody seems to have responded,! ! I'll take a crack at it. The Oracle9i documentation specifically says (in the Oracle9i Database Reference) that either FAST_START_IO_TARGET or LOG_CHECKPOINT_INTERVAL will override FAST_START_MTTR_TARGET. I would tend to believe them. In the Oracle9i Performance Tuning Guide, Oracle contains a note that you should disable or remove the FAST_START_IO_TARGET, LOG_CHECKPOINT_INTERVAL, and LOG_CHECKPOINT_TIMEOUT parameters when using FAST_START_MTTR_TARGET. Setting these parameters interferes with FAST_START_MTTR_TARGET. I don't see where LOG_CHECKPOINTS_TO_ALERT would cause a problem, but if you are suspicious, you might check metalink. As I understand it, the big advantage of FAST_START_MTTR_TARGET is its ease and accuracy. Your management provides a goal for how long your Oracle database can take to reco! ! ver in the situation where it crashes. You simply convert that number to seconds and set FAST_START_MTTR_TARGET. With the ! ! LOG_CHECKPOINT parameters, the settings are derived more indirectly. Of course, there is no free lunch. Setting a shorter recovery time may interfere with performance. Dennis Williams DBA, 40%OCP Lifetouch, Inc. [EMAIL PROTECTED] -----Original Message----- Sent: Monday, November 18, 2002 11:04 AM To: Multiple recipients of list ORACLE-L log_checkpoint_interval parameter? I saw a document mention if log_checkpoint_interval define on ORACLE 9i, the fast_start_mttr_target parameter will be ignore. My question is: 1. we have following on init.ora file: log_checkpoint_interval = 10000 log_checkpoint_timeout = 1800 log_checkpoints_to_alert = true fast_start_mttr_target=300 Do I need remove all the log_checkpoint* on init.ora file? 2. what kind of ! ! benefit that fast_start_mttr_target better than log_checkpoint* ? Thanks ______________________! ! ___________________________________________ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: dist cash 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 offic! ! ial ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS INET: [EMAIL PROTECTED] Fat Ci! ! ty 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). _____ Do you Yahoo!? Yahoo! Web Hosting - Let the expert host your site -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS 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). _____ Do you Yahoo!? Yahoo! <http://rd.yahoo.com/hosting/mailsig/*http://webhosting.yahoo.com> Web Hosting - Let the expert host your site -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS 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.com -- Author: Hately, Mike (NESL-IT) 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).
