XP256 Disk Striping for an Oracle 8.1.7 DataWarehouse

From: Tom Lewis <lewis_uk_at_hotmail.com>
Date: 12 Jul 2001 04:49:21 -0700
Message-ID: <6d8d2ec4.0107120349.37cc7615@posting.google.com>

I have a 400GB Oracle 8.1.7 data warehouse deployed onto a XP256. The warehouse often needs to full table scan tables of c50GB and uses parallel execution to achieve this. The database is using 8K blocks and the DB_FILE_MULTIBLOCK_READ_COUNT is set to 16.

The XP256 has been configured with RAID 5 and a stripe size of 256K. Its 36 disks have been divided into 8 logical volumes of 4-6 disks each with different tables or indexes assigned to each logical volume to avoid contention.

I really need some help on two fronts.

What is the optimal relationship between the DB block size and the stripe size. Currently, I assume that the database will read 32 blocks off disk 1 and then 32 off disk 2 etc. etc. That does not sound very parallel to me. Should the stripe size be smaller?

Secondly, is it necessary to divide the XP256 into different volumes for different purposes or is a larger single volume a better approach?

Many thanks in advance

Tom Received on Thu Jul 12 2001 - 06:49:21 CDT