Advantage off parallel access at external tables

Hi all,

I did some testing to find an advantage of parallel access on external tables. I did an Select count(*) statement on an external table with around 450.000 records. The table reads the data from one file.

But the results are quit different. It takes around 14 to 26 seconds and sometimes the parallel access is faster and sometimes they have the same speed. Is there no real advantage or is the way I'm testing it wrong?

Do I understand the hole parallel access wrong and I have only an advantage at the moment I'm access two or more external files.

I read somewhere (can't find the source again) the parallel access is only recommended on huge external files. Can somebody confirm that?

Thank you very much in advance for you information and help!

Kind regards,

Sebastian Received on Fri Apr 04 2008 - 04:52:41 CDT