15. Apparatus for integrating relational and hierarchical data, schema definitions, and queries in a data processing system, comprising: a memory; and at least one processor coupled to the memory and operative to: (i) convert one or more schema definitions into an intermediate schema language component of an intermediate data language when one or more schema definitions are provided; (ii) convert one or more query expressions into an intermediate query language component of the intermediate data language when one or more query expressions are provided; iii) compile, in an intermediate data language processing engine, at least one of the intermediate schema language component and the intermediate query language component into a run-time representation in accordance with a relational-hierarchical analysis; and (iv) determine whether the schema definitions or the query expressions are relational prior to the converting steps.
16. The apparatus of claim 15 , wherein, in the operation of converting the one or more schema definitions, the one or more schema definitions comprise at least one of relational schema and hierarchical schema.