A heterogeneous database system is described which includes plural database systems, one of the database systems acting as an interface (i.e., system manager). The system manager performs functions which provide an application program with transparent access to the entire database system. The system manager includes a memory for storing (i) a matrix of functional capabilities of each of the plural databases, (ii) a catalog of functions that are supportable by various databases and (iii) and entry matrix for providing an interface function between a user and the system manager. A processor is present in the system manager; and is responsive to a user entry, via the entry matrix, with respect to a functional capability of one of the plural databases, to alter a matrix of functional capabilities pertaining to the database. The alteration is carried out in accordance with a corresponding functional capability entry in the catalog. If a user entry is received which refers to a database for which no entry exists in the matrix of functional capabilities, the system manager presents an entry matrix in a form which reflects default functional capabilities. Thereafter, the default capabilities may be altered by a system administrator to reflect the capabilities of the new database.