Object-based schema integration for heterogeneous databases: A logical approach

In a previous JDM issue, one of the Associate Editors issued a challenge to database researchers to “...encourage us to think about innovation and point out areas that ... are not only important but also open to innovation.†(Pirkul, 1995, p.33). In this editorial, I address one area that Pirkul explicitly identified as a topic for innovation, namely, Heterogeneous Databases. Below I present a novel framework for understanding Heterogeneous Databases and Database Systems. This framework identifies three dimensions of heterogeneity: the “Why†?, “How†?, and “What?†of heterogeneous database systems. I claim that exploring answers to these three questions will help practitioners (1) identify heterogeneous application requirements and map them to appropriate database capabilities, (2) evaluate heterogeneous application techniques that fulfill these necessary requirements, and (3) select products that support the required techniques.

A heterogeneous database management system combines multiple dissimilar models of data within a single integrated system. The objective is to allow a user to access data independently of how it is actually organized. For example, a user may access a database as though it were stored relationally (i.e., in tables) [CODD70], even though it is actually stored as a CODASYL/DBTG or network database [CODA71]. In addition, different subpieces of the database may be organized under different data models. The heterogeneous database system must present these to the user as an integrated whole. The user's model of his data may be different from any of the models chosen to implement it.Rather than construct a new database system from scratch, we are interested in constructing a heterogeneous system out of existing systems. The key difficulties with this approach are: (1) the formulation of database design methods that are applicable to a variety of different data models, and (2) the development of techniques to translate programs and data between dissimilar data models. In this paper, we briefly describe how high level abstraction has been applied to these problems. The use of abstraction in database systems is related to the application of abstraction techniques in programming languages and artificial intelligence research.

In order to operate the distributed heterogeneous database with several different physical, the basic problem must be solved was system integration of the various heterogeneous database system. This paper describes the system integration schemes using S2SH(struts2 spring hibernate) and EJB (Enterprise Java Bean)components based on the B/S architecture of distributed heterogeneous database , the core content analysis for its data management, user data table information query and data table unification.

Database technology is of great variety, structure diversity, solving data integration and exchanges sharing of the heterogeneous database system have became the important problem in all fields. Because of XML is the very important data exchange technology to realize data exchange and transmission ability, this paper mainly explores the data exchange problem how to use XML in heterogeneous database system, , and .Net platform have good support to XML and heterogeneous database system, so the combination of XML and.net, can realize data exchange of heterogeneous database system.

Cost parameters and database statistics are the basis of query optimization techniques. However, in distributed and heterogeneous database systems, acquiring and treating information in order to help the optimization process are often tasks of a global query processor, which adapts its functionalities to a specific system architecture. Moreover, this acquisition process involves a large number of parameters and requires customized methods to retrieve data from specific sources. DIG (Distributed Information Gatherer) is a provider of data statistics and query costs that, through an independent and flexible service, aims to support global query optimization processing in distributed and heterogeneous database systems over autonomous data sources. We have developed a DIG prototype and experimented it with specific wrappers for a query middleware on both semi-structured data sources and an object DBMS.

Logical design of data base systems

: This report details the research efforts into the access of distributed heterogeneous database through an encyclopedia facility. Specifically, several data management tools have been prototyped and are described.... Heterogeneous Databases, Distributed Processing, SQL Query, Data Management, Schema Integration

Corporate information system environments are heterogeneous, consisting of multiple and independently managed databases. Many applications that assist decision making call for access to data from multiple heterogeneous databases. To facilitate this, there needs to be an integrated representation of the underlying databases that allows users to query multiple databases simultaneously. The process of deriving this integrated representation is called schema integration. Schema integration is time consuming and complex, as it requires a thorough understanding of the underlying database semantics. Since no data model can capture the entire real world semantics of each database's objects, this process requires human agent assistance. Although certain aspects of schema integration can be automated, interaction with designers and users is still necessary. We describe a four-level blackboard architecture that supports schema integration and provide a detailed description of the communication among human and computational agents that this system allows.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The issues and solutions for the interoperability of a class of heterogeneous databases and their database systems are expounded in two parts. Part I presented the data-sharing issues in federated databases and systems (Hsiao, 1992). The present article explores resource-consolidation issues. Interoperability in this context refers to data sharing among heterogeneous databases, and to resource consolidation of computer hardware, system software, and support personnel. Resource consolidation requires the presence of a database system architecture which supports the heterogeneous system software, thereby eliminating the need for various computer hardware and support personnel. The class of heterogeneous databases and database systems expounded herein is termed federated, meaning that they are joined in order to meet certain organizational requirements and because they require their respective application specificities, integrity constraints, and security requirements to be upheld. Federated databases and systems are new. While there are no technological solutions, there has been considerable research towards their development. This tutorial is aimed at exposing the need for such solutions. A taxonomy is introduced in our review of existing research undertakings and exploratory developments. With this taxonomy, we contrast and compare various approaches to federating databases and systems.

The issues and solutions for the interoperability of a class of heterogeneous databases and their database systems are expounded in two parts. Part I presents the data-sharing issues in federated databases and systems. Part II, which will appear in a future issue, explores resource-consolidation issues. Interoperability in this context refers to data sharing among heterogeneous databases, and to resource consolidation of computer hardware, system software, and support personnel. Resource consolidation requires the presence of a database system architecture which supports the heterogeneous system software, thereby eliminating the need for various computer hardware and support personnel. The class of heterogeneous databases and database systems expounded herein is termed federated, meaning that they are joined in order to meet certain organizational requirements and because they require their respective application specificities, integrity constraints, and security requirements to be upheld. Federated databases and systems are new. While there are no technological solutions, there has been considerable research towards their development. This tutorial is aimed at exposing the need for such solutions. A taxonomy is introduced in our review of existing research undertakings and exploratory developments. With this taxonomy, we contrast and compare various approaches to federating databases and systems.

Modular equipment design in optimization-based process synthesis

The SIRIUS-DELTA architecture: A framework for co-operating database systems

A multidatabase system consists of several heterogeneous local database systems. Most studies of multidatabase transaction management are concerned with the centralized transaction management in which there is only one coordinator. All global transactions are submitted to the coordinator site, and thus it can be overloaded. If the coordinator site fails, the multidatabase systems cannot serve any global transactions. In decentralized transaction management, since the site to which a global transaction is submitted becomes its coordinator, the load is naturally balanced and the multidatabase system is gradually degraded even though a coordinator site fails. This paper proposes a decentralized transaction management algorithm which guarantees global serializability and local autonomy.

13 - Other Modeling Aspects and Trends

Development of a dynamic data interchange scheme to support product design in agile manufacturing