design multi-division system, How?

We are in the process of developing an application using Delphi 3 C/S and Oracle 7.3. The challenge we have is with multi-division companies. Each user within a division needs to access certain parts of the tables or views. What is the best way of maintaing the user security and audit-trails? Should we logon as a SYSDBA internally and maintain the security within our app or create individual users in Oracle and maintain security rights in Oracle using privilages and roles?
Please send any comments to hassan_at_3log.com. Thanks in advance Received on Thu May 21 1998 - 00:00:00 CDT