Table performance problems with RAW.

Hello all.

We have come across an interesting problem that I thought I would ask the rest of the world if they've seen the same thing.

Our current setup is Oracle 7.3.4 Parallel Server running on AIX 4.2. The performance problem comes when we have tables with a "medium to large" initial extent (50M) and are performing unindexed full table scans of the tables, such as in a SELECT COUNT(*) FROM EMP. These selects are taking a very long time on EMPTY TABLES. I have not seen this behavior in the "cooked" file system world, and about the only thing I can attribute it to is running on RAW file systems. The larger the initial extent, the longer the select time and vice-versa.

Currently we've gone through our code and tried to find all the full table scans and make them indexed reads, and have shrunk down the size of some tables where we cannot force an indexed scan to get around the situation. However, I believe there must be some type of RAW tuning parameter somewhere that will alleviate some of our problems.

Any suggestions/comments about this? Received on Thu Sep 17 1998 - 14:14:27 CDT