Russel,

>In an Client-Server application where the customer insists on a specific Primary key (say ID C(10)), I wish to discuss the pros and cons of the following methods of inserting a new record.
>
>(a) Check if the new primary key (Say ID = "JFK"), exists in the Backend table using INDEXSEEK or SELECT-SQL, then lock the WHOLE table while the INSERT is being performed.
>(b) Try to insert the record without checking, trap and deal with any error returned ie "Duplicate Primary key"
>(c) Any other suggestions?

IMO, (b) is the most secure one, With (a) you still cannot guarrantee for 100% duplicates can't exist. If with (a) somehow a duplicate was inserted you won't notices and could get odd behaviour in your app.

Walter,