I'm really interested in extracting information about a database structure from a production database in order to determine which tables are currently being used and/or are linked to other tables, and which tables are not being used and/or are isolated. Before I joyfully dive in and start writing code, is there a tool or module that does this already? (It's a rather large DB2 database.)

Something that draws pretty pictures based on the resulting information would be even cooler, but that certainly isn't a requirement.