>>>Yes, that's true. But I have LOCATE command after COUNT is done, so everything seems to be OK.
>>
>>If you would add an index to the cursor or table in the bottom grid, you could use SET KEY TO instead of SET FILTER for the best speed. If the cursor is at EOF in the bottom grid, there are no matching records to validate.
>
>I need to filter based on combination of two integer fields. I think I did consider SET KEY originally when I designed the form, but at the end decided otherwise and used SET FILTER. Since it's working and in production, I don't want to do a major overhaul.

No excuses. You can convert two integers into strings and index on that. It's no major overhaul.