Re: Database Parameters and Redo Log Contention

Gary Corless wrote in message <7cqre0$ls5$1_at_news1.news.iol.ie>...
>I work in a small IT dept and picked Oracle as the database for our new
>system. The problem is it's hard to know what sizes things should be (the
>default sizes seem very small). I've got 53 Redo Log Contentions within
the
>first 2 weeks of the pilot project. The application is not yet critical so
>db recovery currently set for 3 days.
>
>Question 1 : Are the SGA sizes to big/small?
May be you should decrease SGA a little bit, especially shared_pool not db_buffers. It depends of paging activity. If your paging space is lightly used, let it be so...

>
>Question 2 : Would increasing or decreasing the redo log sizes ,
>log_checkpoint_interval or log_checkpoint_timeout reduce the Log
>Contention?

Hmm....
Add more redo logs or increase their size (you should drop them and recreate)
Just try to keep your total log file space at least 1.5 times bigger than DB cache in SGA (db_buffers).
You have ca 200MB DB buffers, so create additional logs or increase their size so you have at least 300 MB logfiles. Then your database will not stuck (with "checkpoint not complete" warning in alert_log) periodically when you run large insert/update statements and run out of free log space.

AND INCREASE log_buffer size !
At least to 1.5 of biggest logfile size.

---
Hasso Brück
Technical Manager
Korel SYS Ltd. Received on Thu Mar 18 1999 - 10:04:34 CST