Re: Improving Performance of Hash Joins

zigzagdna_at_yahoo.com wrote:
> I am on Oracle 10.2.0.3 on Windows 2003 32 bit. I have /3GB switch set
> on and have a value of sga_target set to 2.x GB,
>
> I am using a third party package and many queries are doing hash
> joins. I cannot modify any queries because of no source code available
> to me. I know in Oracle9i, there was some init.ora parameter for
> specifying memory used by hash joins which has been taken away in 10G.
> What are my options (if any) to improve performance of this hash joins
> which for some queries take 2-3 minutes.

Your assumption that you can not modify the queries is incorrect. You can easily do so with the DBMS_ADVANCED_REWRITE built-in package.

Go to Morgan's Library at www.psoug.org and look up the package. The demo will show you how to do it.

-- 
Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org