HEURISTIC ALGORITHM FOR FRAGMENTATION AND ALLOCATION IN DISTRIBUTED OBJECT ORIENTED DATABASE

Class fragmentation and allocation is an important technique to improve the performance of a distributed object oriented database system. The class fragmentation is to split a class into smaller pieces in distributed databases aims to reduce the access to unnecessary data, the allocation is to locate fragmented classes into the sites in the connected network properly to reduce the cost of data transmission. Classes in object databases include attributes describing the characteristics of the object, methods describing the behavior, and relationships with objects with other classes, including relations inheritance. With such characteristics, class fragmentation and allocation in the distributed object oriented database system is more complex than fragmentation technique and design of relational databases. Fragmentation techniques applied in the design of distributed object-oriented database today often do not use cost between the sites, fragments are allocated to the site after getting a fragmentation method of data objects. This paper proposes an algorithm of fragmentation and allocation simultaneously, including the cost of data communication between the sites used for fragmentation to reduce communication costs when processing and querying distributed data

Partitioning Schemes for Object Oriented Databases

In order to support homogeneous distributed object oriented database systems we need to have a clear understanding of what is meant by partitioning a class and what are the different ways of doing so. In this paper, we concentrate on studying the different types of class partitioning schemes that can arise in object oriented databases. By laying down the foundation by articulating the concepts, representation, and implementation approaches for partitioning object databases, we facilitate further work on partitioning algorithms, query decomposition, optimization and transaction management for distributed OODBMS. 1 Introduction Object oriented databases (OODBs) have been gaining popularity since late 80's when several OODBs became commercially available. Earlier work on OODBs has mainly concentrated on centralized database environments, and only more recently has OODBs technology been applied in distributed systems environments (e.g. client-server and and federated multiple-databases [..