Re: ORACLE on LINUX

Thornton Prime wrote:

> While our projects are relatively small, a key component is
> access time and I understand that Oracle on SCO using the raw
> partitions greatly improves performance. Are you saying that this
> is only the case for extremely large databases (> 1G)?
>

A small word of advice - don't bother with raw patitions unless you have tried and failed to get the performance you need using file-systems. Even then do A LOT of benchmark testing before moving to raw.

Bear in mind that with raw partitions you'll not benefit from unix file-system caching. This can (in some cases) lead to raw giving substantial decreases in performances compared to f/s.

Also the maintenance head-ache of raw almost always outways any gain.

also, the biggest gain I've seen is less than 10% - and this was in a specific situation against a ufs file-system. Most file-systems these days employ a much improved read-ahead and caching strategy which can often out-perform raw. Remember that raw can only ever read 64K at a time, where-as most post ufs filesystems  will read more in one i/o request.

Tuning your application will amost certainly give you a better return on time than raw.

PS These notes are based on experiences with databases up to a couple of Terabytes.

simon. Received on Thu Jun 25 1998 - 00:00:00 CDT