I'm looking to resize our online redo logs for a particular app and am somewhat confused about the appropriate settings. The current config is 4 groups (2 members each) of 5Mb size. We cycle through a daily average of 750 logs in a 22 hour period. During a more intensize daily batch window of 5 hours there is an average of 100 per hour switches i.e. two thirds of switches are occuring during the batch window.
I'm planning to resize the online redo logs to 120Mb based upon rationale of 500Mb per hour in batch window and 4 groups. So switching will happen apporox every 15 minutes. Some Oracle documentation suggests 1 switch per hour is best and others one switch every 30 minutes. So question 1: Does this proposed resize make sense? Our current log_checkpoint_interval = 10,000 which means a checkpoint at approx 39Mb given it's a Win 2k OS with it's OS block size of 4096. So question 2: Does it make sense to leave this setting as is and have approx 3 checkpoints per each redo (timewise every 5 minutes) or is there a better value and why? (Support suggested setting to zero, i.e. effectively ignore!). The log_checkpoint_timeout is currently 1800. Support suggested setting this to zero but the reference manual suggests that this should not be done!. So final question: What would the best value be given the log_checkpoint_interval would probably have a checkpoint every 5 minutes using heavy processing?. Your considered opinions/input re above would be much appreciated. ------------------------- Seán O' Neill Organon (Ireland) Ltd. [subscribed: digest mode] -------------------------------------------------------------------- This message, including attached files, may contain confidential information and is intended only for the use by the individual and/or the entity to which it is addressed. Any unauthorized use, dissemination of, or copying of the information contained herein is not allowed and may lead to irreparable harm and damage for which you may be held liable. If you receive this message in error or if it is intended for someone else please notify the sender by returning this e-mail immediately and delete the message. -------------------------------------------------------------------- -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: O'Neill, Sean 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).
