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Message Posted: Wed, 10 Sep 2003 @ 12:53:47 GMT

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Craig,

Here's my simple "rule of thumb", however I use Disk to CPU rather than CPU to disk. It really makes no difference, I just prefer whole numbers.

0-200       Bad
200-500     Fair
500+        Good

If I see this metric get below 200, it's almost a guarantee that the request is performing a significant product join or a poorly designed outer join.

Using your data, I added this ratio to the table as follows:

Date         HR    Username    CPU      DiskIO    Ratio

9/3/2003     19    USERA       12197    262638     21.5
9/2/2003     20    USERA       11902    263475     22.2
9/2/2003     18    USERA       11524   1532749    133.0
9/3/2003     16    USERA       11569   1868715    161.5
9/3/2003     13    USERB         295    106476    360.9

It's just one of several metrics to be reviewed when evaluating query performance, but I find it invaluable.

Regards,

Thomas F. Stanek
TFS Consulting, Inc.

www.tfsconsulting.com

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