Re: Loss of Both current redo logs

Flora Seymour schrieb:
>
> Hi
> ...
>
> We have fairly large redo log files (100m) to prevent frequent switching
> during our nightly batch processing that does a lot of large updates. This
> means that during our online day, where we have *alot* of small update
> transactions (customer requests), our log files do not switch at all. >
> What negative side effects would forcing a switch every 15 minutes imply? Is
> this a bad idea? Am I understand this correctly? Am I overly paranoid?
>
>
> Thanks in Advance for any input...
> Flora

With these sizes I assme your database is not a toy but really important.

You schould mirror your archive logs at least once on different disks.

The control files should be mirrored 3 or 4 times. they do not change that much and are small.

I assume too, you use your database in ARCHIVELOG mode. I don't see big problems using a forced redo log switch all 15 minutes. The amount of moved data is about the same when the 100M are archived at once or you archive a party filled redo log group cause only the filled part of your redo log group is archived. Extremely the are only some KB copied only containing header information if you switch your log and there was silence between the switches.

To get a larger time buffer, you should create a third redo group. If one group is archiving and during that the other group is full, your instance is frozen until the other group finished archiving and is ready again.

Good luck
Kai Received on Tue Jul 21 1998 - 15:10:13 CDT