To measure it, just run both on a huge table or in a loop for 100000-1000000 times and take the time using SECONDS(). In order to have a real comparison, it's good to have total times of at least several seconds.

Vlad

>I usually use the '$' althogh have been told at() was faster.. but, I don't see how that could be measured.
>
>select * from inventory where 'MIC' $ upper(descript)
>
>BOb