We suggest a new approach to database updates, in which a database is treated as a collection of theories. We investigate two issues: simultaneous multiple update operations and equivalence of databases under update operations. 1.

We suggest here a methodology for updating data- The ability of the database user lo modify the con-bases with integrity constrain & and rules for deriving inex- tent of the database, the so-called updale operation, is fun-plicit information. First we consider the problem of damental to all database management systems. Since updating arbitrary theories by inserting inu, them or delet- many users do not deal with the entire conceptual database

To achieve data sharing among heterogeneous database management systems, one essential step is the conversion of the schemata defined in the diverse data models used by these systems. A semantic preserving translation of different modeling constructs and constraints is necessary to ensure that the semantics of applications remain intact after the translation. In this paper, we present an object-oriented extensible core model (ORECOM) which is used as a neutral, intermediate model through which diverse modeling constructs and constraints are translated. The model provides very general and primitive structural constructs in the forms of objects and binary object associations for representing the structural properties of various high-level data models. It also provides behavioral constructs in the forms of operation specifications and semantic rules with triggers for capturing the semantic constraints of these high-level models. Different from the intermediate models used in the existing ...

The paper contributes to the elaboration of a methodological framework for solving the problem of data model heterogeneity in the interoperable information resource environment. It presents an approach to rigorous definition of data models and to the handling of them as formal objects provided for the development of data model mappings in the process of design of heterogeneous information resource environment. The paper defines strict principles and specific techniques facilitating verifiable design of commutative data model mappings. The methods introduced make it possible to construct generalized data model kernel extensions equivalent to various internal data models and to develop and verify algorithms of the generalized level DML interpreters 1 . 1 Introduction This paper (published as [23]) contains the results defining an approach for equivalent transformation of heterogeneous data models. Partly the results are based on the experience in the development and applicatio...