topic Re: Oracle 8.0.5 performance issues. in Operating System - HP-UX

Oracle 8.0.5 performance issues.

Robert Hoey — Fri, 19 Jan 2001 18:25:23 GMT

HP-UX 10.20 on K580.

Good afternoon everyone.

We are going to use extent striping over three 18 GB disks which will contain an Oracle database. This is the first time I am working with Oracle and my biggest concern is the performance hit that we will take.

My question: Since we are using extent striping we are limited to the default system block size which is set to 8Kb. Has anyone had any performance problems running an Oracle Database on disks that are striped with an 8Kb block size? What is everyone else out there using for a block size on disks that contain an Oracle database?

Thanks in advance.

Re: Oracle 8.0.5 performance issues.

Joseph C. Denman — Fri, 19 Jan 2001 21:18:44 GMT

normaly the same as the OS. You will be fine using 8K block sizes.

Re: Oracle 8.0.5 performance issues.

Carlos Fernandez Riera — Sat, 20 Jan 2001 17:46:31 GMT

For online applications 8k block size is good for Oracle.

A block of 64k is used for datawarehouse environments.

You can tune multi_read_count( more or less) to 3 in init.ora, so each oracle read will read one block for each disk.

Re: Oracle 8.0.5 performance issues.

Andreas D. Skjervold — Mon, 22 Jan 2001 08:33:38 GMT

Hi!
Here is how I see it ( if I have understand your question right!)

Using filsystems for data storage; any Oracle block size (db_block_size) which is a multiple of your 8k stripe size should be OK, since hp-ux is caching the blocks anyway.
If your're using raw devices (async I/O) the Oracle block sizes should be equal (8k), since Oracle is doing all the caching.

Andreas