Re: Oracle DB Design Question

> I know oracle can stripe the data files for performance and
> redundancy. Will I get better performance from this than simple
> hardware RAID ?

I think I remember reading something about this years ago but I don't know whether this feature is still available in current versions of Oracle. You can definitely locate individual Oracle data files on different disks to improve performance and to help minimise I/O bottlenecks. I think hardware RAID would be a better option for the following reasons: -

1 If the striping/mirroring is done by separate hardware in the RAID controller, you will have less load on your CPU and therefore better performance.

2 RAID disks will protect your operating system files and Oracle executables as well as your Oracle data.

3 If RAID is implemented correctly, I believe it can yield performance improvements when compared with the same system without RAID.

I believe Oracle recommend RAID level 1 for files that are mainly written to (e.g. redo logs) and RAID level 5 for files that are mainly read (e.g. the data files).

>
> Is there any recommendation from Oracle on what percentage of RAM can
> be allocated to SGA without making the OS do swapping ?

This would depend on how much RAM is required by the operating system and any other applications running on the server. Oracle has some very useful tools to show you how performance would be affected by allocating more RAM to the Oracle memory structures. These tools are very useful for balancing the memory requirements between operating system and Oracle.

Good luck,

Richard Received on Mon Sep 08 2003 - 13:45:27 CDT