What database are you using? If it is SQL Server or Oracle, I would consider writing a trigger for the insert/update/delete actions. That way, any changes made to one table can be immediately affected upon the other table. You can even traverse databases with the trigger code.
Another alternative would be to schedule a job on the server to do the updating.
Either of these would be the preferred solution as it keeps all activity on the server, thus cutting down on the amount of traffic between the client and the server.