My team will develop an internal (known users) application that has an architecture based on Java as front-end and PL/SQL as back-end. So, currently we are thinking in a better solution to manage the user/permissions, and we have two options:
Each user has their own database account, granted with the permissions. Currently the legacy system use this approach and I don't like it because it manages permissions based on database objects' granularity. So, I believe it is a bad choice to have a database connection per user. Can you see more cons here?
Build some tables at database to store the users and theirs permissions/profiles and build a PL/SQL procedure to do the login, generating a token and include a parameter to all others PL/SQL to verify this token and then authorize (or not) the execution.
So, you can ask me: why not just manage your permissions in your web-application? Answer: Those PL/SQL are already done and are used by all legacy systems, and this web-application should behave according it (ie. User permissions should be managed by the PL/SQL and its granularity based in please.)
How do you proceed in this case?