AM - I think that you will find that using a SQL database will give you a major advantage in situations where you are dealing with:

• More complex data than just a single field
• An application that does more than just "get everything in the database".

In your situation, it might be worth doing some benchmarking. It wouldn't be too hard to set up a time test comparing reading in all the records from the DB and reading in all the records from a file. I think that if you can prove to your coworkers that the load is minimal then you should go with the file. Of course, this does depend on how often you expect to be performing this operation.