Our strategy for exploring heterogeneous MBDs involves additional OPM tools that provide facilities for (1) constructing OPM views for MBDs developed with or without OPM; (2) assembling MBDs within an OPM-based multidatabase system, while documenting MBD schemas and known schema links between MBDs; and (3) expressing, processing, and interpreting multidatabase queries in this multidatabase system.