IMO, LOCATE examines the TAG that corresponds to any existing filter statement and builds a bitmap. SET KEY works like SEEK which has to hit the index tag a smaller number of times to find the first record.

This is why SET KEY can improve performance used instead of a filter on a grid.

If you use GO TOP in this case, you may find it works faster and doesn't C005.


>HI,
>
>I've a large table (100K+ records that takes up about 75MB) that is giving me fits (C000000005 errors) when the follow is done:
>
>SELECT lsealt
>SET ORDER TO TAG lseacctnum
>SET KEY TO m.lseacctnum && variable assigned a value
>LOCATE
>
>Usually the LOCATE causes the problem. But to make matters more confusing is that I don't get this when I use VFP6. Only when running the code in VFP7.
>
>I've recreated indexes, copied the records to a Temp table and renamed it back. Nothing works. I don't want to compile under VFP6.
>
>Anyone know about any quirks with SET KEY TO ?
>
>Thanks