[Zope] Z Database Connections - pass uid/pwd to RDB

When you create a Z database connection you must supply a fixed connection string with a fixed uid/pwd to open that connection. So every user that connects to Zope connects with the fixed uid/pwd to the relational database. Is there any way or workaround to dynamically pass the Zope uid/password to the relational database? This is important when user security is maintained by the database scheme. Not that I really want this feature for my use but we have projects where the customer has the database model ready and wants the users to be individually authenticated at the relational database (in this case: Oracle). thanks Philipp Auersperg(zwork)