What do you think is the best method to control db access when writing a
frontend app? For discussion purposes, let's assume:

1. The app will be written in Java
2. The app will work with (almost) any DMBS and avoid vendor-specific
features
3. We would like to grant access to groups/roles as well as specific users
4. We would like fine-grained access control, to the column level

Is it better to use the built-in DBMS access control, or write custom access
controls into the app?

Harry Stangel