>>All you have to do is create an index on Empty( < field > ) and then both the Empty and Not Empty will be optimized.
>
>I do not recommend this. Any condition, especially on "not empty()", would return a LOT of records from the index, just to do Rushmore Optimization. Thus, a query would be "Full Rushmore Optimized" by definition, but not fast. My recent FAQ on Rushmore Optimization explains the details of how this works.
>
>Hilmar.

In the example I posted to Jay, I have 2.5 million records. Here I need to check for D40CkNo being empty. I've run the following performance test.

lnSeconds = Seconds()
Count For D40CkNo = ' ' To N1 && .845 2,497,224 records
?"1a1", Seconds() - lnSeconds
lnSeconds = Seconds()
Count For Empty( D40CkNo ) To N1 && .444 2,497,224 records
?"1a", Seconds() - lnSeconds

In this case because the speed of the Empty( < field > ) is twice as fast.