Slash Boxes
NOTE: use Perl; is on undef hiatus. You can read content, but you can't post it. More info will be forthcoming forthcomingly.

All the Perl that's Practical to Extract and Report

use Perl Log In

Log In

[ Create a new account ]

djberg96 (2603)

  (email not shown publicly)

Journal of djberg96 (2603)

Thursday October 28, 2004
12:59 PM

When explain plans lie

[ #21572 ]
A better explain plan always means better performance, right? Wrong. Consider the PARALLEL hint in Oracle. I can get a great looking explain plan with something absurd like this:

select /*+ parallel(table,32,32) */

But, if you time this, the performance sucks rocks because there aren't nearly that many striped disks, and the hint ends up working against you. This is why you should always ask for information (i.e. number of cpu's, striping, etc) about the hardware that the Oracle server is actually sitting on.

The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
More | Login | Reply
Loading... please wait.