>What is the most efficient way of handling this?
>Assuming I have a compound PKEY or CANDIDATE
>should I do a SEEK before modifying a one of
>the components or is it more efficient to trap
>for the error?

Because of all the possibilities of optimistic buffering and other users editing the same record, changing data that make up unique keys, you are better off trapping the error. The best way is to have a surrogate integer PK field that can not be modified [or even be seen] by the user. Then use a PK generator to populate all your PK fields. Then use Candidate keys for user editable data and error trap those duplicates.