Re: Granting table privileges

"Chuck" <chuckh_at_softhome.net> wrote in message news:Xns935EA82C339A5chuckhsofthomenet_at_130.133.1.4...
> I completed my tests today. Same tests, the only difference being I used
> two volumes that were not striped. With both index and table on the same
> volume to insert 500k rows it consistently took twice as much time as when
> the table and index were physically separated. I stand by the conventional
> wisdom that says separating tables from their indexes yields a measurable
> performance increase.
>
> My average time to insert with both on the same disk was 1:14. With the
> segments separated it was 2:30.

Now repeat the test with updates.

And is that '2 minutes 30' or '2.3 seconds'?

And don't average. Report the runs accurately. And describe your hardware *fully* (processor, RAID controller, disks, nature of box, O/S etc).

And since there is no physical possibility of what you are claiming, make sure you eliminate every other factor. Eliminiate results of caching between runs, for example; and make sure there is no extraneous, non-Oracle or non-Test, I/O going on.

And in the meantime, enjoy this snippet from Tom Kyte (May 2002):

Quote on....
>call me a dreamer, but if you put tables and indexes in same tablespace
>and spread that tablespace over a number of devices you get EXACTLY the
>same result as above.

you might even find you get BETTER ;)

the goal -- even IO distribution.

puttting indexes on disk1 and data on disk2 -- you may well find your index (much more cacheable in general then the data) results in very very little physical IO to disk 1. Disk 2 on the other hand it getting beat up.

stripe disk1 and disk2 and you'll get even io in this simple case. Quote off....

HJR Received on Tue Apr 15 2003 - 17:12:02 CDT