Re: Increase frequency of log switches

> First, if you are properly set up in archive log mode, have duplexed
> redo log groups, and are taking regular backups, the amount of data
> lost in the event of "a major machine failure" is already near zero,
> and has nothing to do with the frequency of log switches.
>
> Second, the reason you don't find a parameter to control the maxsize
> of a redo log before a switch is because there is none. You're redo
> log files are a fixed size. A switch occurs when one fills up or you
> manually issue ALTER SYSTEM SWITCH LOGFILE.

Thanks - Yes i already have everything running as you state and can recover the whole instance onto a test machine.

My query though is that if online redo has not been archived then this is not included in the backup. Therefore the time from last RMAN backup to failure could, in my case, be around a day. If i could have the online redo archived more often i would reduce this potential data loss.

Seems i need to run ALTER SYSTEM SWITCH LOGFILE every couple of hours to make sure i minimise this loss. This is as i don't backup online redo as per the information i have found.

FYI - when i say 'major machine failure' i mean the building burns down or all disks eat themselves at the same time. As i have archived logs, backup control files and RMAN backups being duplicated offsite then i can maintain minimal data loss providing i can reduce the time between log switches. Unless i have completely got the wrong end of the stick.

thanks for all your help Received on Thu Jul 08 2004 - 11:11:11 CDT