Re: Speeding up the redo logs

I have implemented a very fast redo log setup, but it is not cheap. My average write times to online redo logs are 0.1 to 0.3 milliseconds. And I wholeheartedly agree that in a write intensive database, redo log time can be critical.

However, I also agree with some of the other posters that you have to try to work on your procedures and tuning to minimize the load you are forcing the database to do.

I have two separate disk arrays on separate SCSI controllers to be used only for the online redo logs. Log copy A goes on one array's drives, Log copy B on the other array. Each log file in the online rotation goes to a separate drive in the array, so that log archiving of the previous logfile does not interfere with writes to the current online log.

Do not use RAID striping for your online redo logs - it serves no purpose.

Finally, I have my redo logs on Veritas Quick I/O, which eliminates unnecessary OS buffering that Oracle is accomplishing, anyway.

The whole point of all of this (except qio) is to isolate the I/O to the redo log file from ALL other I/O activity.

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http://www.deja.com/ Received on Sun Jan 21 2001 - 07:43:03 CST