Heterogeneous Distributed Database Management System Research Articles

Atomic commitment and resilience in grid database systems

Atomic Commitment Protocol (ACP) is an important part of any distributed transaction. ACPs have been proposed for homogeneous and heterogeneous distributed database management systems (DBMS). ACPs designed for these DBMS do not meet the requirement of Grid databases. Homogeneous DBMS are synchronous and tightly coupled while heterogeneous DBMS, like multi-database systems require a top layer of multi-database management system to manage distributed transactions. These ACPs either become too restrictive or need some changes in participating DBMS, which may not be acceptable in Grid Environment. In this paper, we identify requirements for Grid database systems and then propose an ACP for grid databases, Grid-Atomic Commitment Protocol (Grid-ACP). We then extend Grid-ACP to handle failure of database sites.

Query transformation in heterogeneous distributed database systems

A heterogeneous Distributed Database Management system is organized as a federation of nodes with different functional capabilities and using different nodal query languages. The problem of query decomposition and translation is investigated and two approaches are identified as direct translation and a translation using an intermediate canonical language. The use of universal symbolic manipulation techniques instead of dedicated cross-translators to perform query transformation is suggested.

A query processing algorithm for a system of heterogeneous distributed databases

This paper presents a query processing algorithm, formulated and developed in support of the prototype architecture of the Distributed Access View Integrated Database (DAVID) which is a heterogeneous distributed database management system. The objective of the proposed query processing algorithm is to produce an inexpensive strategy for a given query. The inexpensive query strategy is obtained primarily by computing the most profitable semi-joins and by determining the best sequence of join operations per processing site. The latter is obtained by applying a zero-one integer linear program that uses a non-parametric statistical estimation technique to compute the sizes of the temporary clusters. A cluster is a subset of the cartesian product of a list of atomic and non-atomic domains and is the structure that can represent in a uniform way data stored in relational, hierarchical and network databases. Following some background information on the development of the DAVID prototype, this paper introduces the schema architecture. The schema architecture describes the mechanism by which the component heterogeneous database schemata are mapped into the uniform global schema. This is followed by the formulation of the query processing algorithm, its implementation and an illustration of its use in the context of NASA's Astrophysics Data System.

MDAS: heterogeneous distributed database management system

An approach is described to heterogeneous distributed database management system (DBMS) design, and a prototype implementation based on this approach called the multiple database access system (MDAS) is presented. This system acts as a frontend to multiple local DBMSs, which continue to perform all data processing. The current MDAS implementation involves two different commercial microcomputer-based local DBMSs residing on separate machines, which are joined by a serial connection. The MDAS services queries on an integrated view of semantically related databases exhibiting a range of schema and data conflicts.

Integrating logic and object paradigm in HDDBMS

The existing heterogeneous distributed database management systems (HDDBMSs) which are business-oriented will not be able to adequate for many new and developing information processing applications. The important objectives of these applications include the processing of complex objects and intelligence. Our approach is integrating logic and object paradigm to provide knowledge representation and inference mechanism in HDDBMS. This paper decribes the knowledge representation in object-oriented heterogeneous distributed database system with semantic association — OHDDB-DG1, presents the method of processing constraints and rules in the global language OSAL which is Object-oriented and of Semantic Association with Logic, and explains briefly the peculiarities of processing inheritance and recursive inference.

Intent: an integrated environment for distributed heterogeneous databases

Intent: an integrated environment for distributed heterogeneous databases