Re: Question about sizing log files

Chuck wrote:

> We currently have our redo logs set to 20mb and we get an average of 4
> log switches per minute. Just wondering how high people tend to set redo
> log sizes on very busy OLTP database. We are currently running 8.1.7.4
> on Solaris 8 64-bit. We are currently trying to migrate to 9.2.0.1.
>

This becomes a 'philosophy' question ... basically how much paper backup do you want to keep in case the systems fails. It's really a balance between cost of data protection and cost of CPU cycles to accompdate the load for high data protection.

Generally I try to configure the redo logs to switch for 10-15 minutes at 'normal busy load'. In some cases this has required log files of 150 or 200 MB. You indicate 80Mb/minute or roughly 800Mb in the 10 minutes I'd target; that's slightly high for my taste but not totally unreasonable. Flip side, depending on the speed of disks, archiving the 800Mb logs might cause a noticable stutter in which case I'd probably head back down to 150-200 again.

Are you getting that 80Mb/min rate continuously? Or is that a peak load? (If continuous & it's an order entry system, I want the stock-ticker!) Received on Wed Apr 02 2003 - 16:50:56 CST