>>>empty(date) = glempty_or_not
>>>
>>>and set glempty_or_not to .T. or .F. depending on what the user wants
>>
>>Excellent solution, and can be implemented through View Designer too.
>>Surely, it's better to have index tag on empty(date).
>
>No need for that - I think Empty() is optimizable if expression we are
>checking is optimizable.

IMHO, index tag would be helpful anyway whatever optimization potential of the expression.