This is the followup to
DERBY-1823 that Francois Orsini suggested.
I've been experimenting and reading the Developer's Guide section on SQL authorization (User authorizations, cdevcsecure36595).
It appears that the only use of SQL authorization mode is to restrict user access, not to expand it.
For example, if you set the default connection mode to noAccess, a user with fullAccess can't grant any privileges to a user with noAccess. And presumably if the default connection mode is readOnlyAccess, a user with fullAccess can't grant any privileges beyond SELECT, which the user has anyway.
Only if the default connection mode is fullAccess is SQL authorization mode meaningful. That means that a fullAccess user can use GRANT to restrict another user's privileges on a particular database that the user owns.
I'm running into a problem at the end, though. At the beginning of the program, as nobody in particular, I was able to create several users, some of them with full access. But at the end of the program, it seems that even a user with full access isn't allowed to turn off those database properties:
Message: User 'MARY' does not have execute permission on PROCEDURE 'SYSCS_UTIL'.'SYSCS_SET_DATABASE_PROPERTY'.
This seems a bit extreme. I know that with SQL authorization on, "the ability to read from or write to database objects is further restricted to the owner of the database objects." But the ability to execute built-in system procedures? Can I log in as SYSCS_UTIL? How?
I realize that having access to SYSCS_SET_DATABASE_PROPERTY would allow me to in effect delete myself – but that's essentially what I do at the end of the program that sets derby.connection.requireAuthentication but not derby.database.sqlAuthorization.
The documentation does say that once you have turned on SQL authorization, you can't turn it off. But it doesn't say that you can't turn anything else off, either!
I'll attach the program I've been using. Most of the stacktraces are expected, but I'm stumped by that last one.