The paper is devoted to the analysis of the basic features of the object database standard ODMG-93. We analyze ODMG-93 type system under requirements of systematically clear definition of type lattice (including type generators, definition of subtyping relationship for built-in and user defined types, interrelationship of mutable and immutable values, axiomatization of relationships) and of clean multi-level user type creation operations.
We analyze ODMG-93 query language under the requirements for clean support of the object creating queries treating types as algebraic systems. Such requirements lead to the necessity of providing of a well-defined type inferencing and integrating of the derived types into the type lattice. Cartesian product and binary set expression operations applied to sets of objects need more precise definition based on the interpretation of such sets as algebraic systems.
We conclude that more systematic and uniform way of type lattice, type inferencing and set operations definition is required and show possible ways how such definition could be reached.
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