The transformation of existing local databases to meet diverse application needs at the global level is performed through a four-layered procedure that stresses total schema integration and virtual integration of local databases. The proposed methodology covers both schema integration and database integration, and uses a four-layered schema architecture (local schemata, local object schemata, g...

Data integration helps in manipulating data transparently across multiple distributed databases. The purpose of integration system is to provide a unified global view to the user over various heterogeneous data sources. To answer user queries, a data integration system employs a set of semantic mapping between global and local schema. Such integration has challenges of creation of local and glo...

| Several methodologies for the semantic integration of databases have been proposed in the literature. These often use a variant of the Entity-Relationship (ER) model as the common data model. To aid the schema conforming, merging and restructuring phases of the semantic integration process, various transformations have been deened that map between ER representations which are in some sense eq...

This paper presents a new approach to schema evolution which combines the activities of schema integration and schema evolu tion into one framework In previous work we have developed a general framework to support schema transformation and integration in hetero geneous database architectures Here we show how this framework also readily supports evolution of source schemas allowing the global sc...

In a heterogeneous database system which consists of object databases, a global schema created by integrating schemas of the component databases can provide a uniform interface and high level location transparency for the users to retrieve data. The main problem for constructing a global schema is to resolve connicts among component schemas. In this paper, we deene corresponding assertions for ...

Several methodologies for the semantic integration of databases have been proposed in the literature. These often use a variant of the Entity-Relationship (ER) model as the common data model. To aid the schema conforming, merging and restructuring phases of the semantic integration process, various transformations have been deened that map between ER representations which are in some sense equi...

This paper presents a new approach to schema evolution, which combines the activities of schema integration and schema evolution into one framework. In previous work we have developed a general framework to support schema transformation and integration in heterogeneous database architectures. Here we show how this framework also readily supports evolution of source schemas, allowing the global ...

A practitioner’s approach to integrate databases and evolve them so as to support new database applications is presented. The approach consists of a joint bottom-up and top-down methodology; the bottom-up approach is taken to integrate existing database using standard schema integration techniques(B-Schema), the top-down approach is used to develop a database schema for the new applications(T-S...

One of the challenging problems in the multidatabase systems is to find the most viable solution to the problem of interoperability of distributed heterogeneous autonomous local component databases. This has resulted in the creation of a global schema over set of these local component database schemas to provide a uniform representation of local schemas. The aim of this paper is to use object-o...

We have developed a software prototype toolkit called Bellcore Schema Design and Integration (BERDI). Its goal is to support a pragmatic, flexible, faster, and accurate process of designing new schemas (including data model integrity constraints and extensive dictionary information) as well as managing multiple schemas. Emphasis of BERDI so far has been on the analysis, interdependency specific...