Malcolm C. Taylor

Integration of database systems using an object-oriented approach

With ever-increasing amounts of data being stored on computers, there is a growing demand for systems that will support convenient access to data that are distributed across multiple databases. The authors describe an object-oriented language which supports the definition and use of partially integrated views of a collection of autonomous database systems. They provide a classification of incompatibilities between autonomous databases, in order to define multi-database classes and messages and the subclass/superclass hierarchy. User queries are expressed in a uniform object-oriented language based on Smalltalk.<<ETX>>

Integrating sets, rules, and data in an object-oriented environment

The Tanguy knowledge-base management system, which integrates rule-base, database, and object-oriented paradigms to capture the advantages of each, is discussed. Tanguy provides set-oriented interfaces, data-driven production rules, and permanent object storage in a C++ environment. The need for integration of the three paradigms is reviewed. The Tanguy architecture, the data model used in Tanguy, and Tanguys production rules are described.<<ETX>>

Integration information systems using an object-oriented approach

With ever-increasing amounts of information being stored on computers, there is a growing demand for systems that will support convenient access to information that is distributed over multiple information systems. In this paper we describe a system called KOPERNIK * , which uses an object-oriented approach to define partly integrated views of a collection of autonomous information bases. These views, as well as multi-information-base queries, are described using a language-independent meta-model

Distributed processing of queries for XML documents in an agent based information retrieval system

The paper addresses the problem of efficiently querying large numbers of text documents using parallel processing methods. The optimization criteria are somewhat different from those used in querying heterogeneous databases, largely because the extraction of ontological information from documents is the dominant component of query execution time. We assume that each document has been previously annotated using XML. The authors describe the architecture of a system to process ontology based queries for XML annotated documents. We have introduced two basic strategies for query processing: simple strategy, and semi-join strategy, and their possible extensions using pipelining and longer lists for keyword search. Different levels of parallelism for these strategies are discussed. An evaluation model is created and used to derive optimal replication of resource agents. The theoretical and experimental results are compared.

Integration of object-oriented programming languages and database systems in KOPERNIK

Abstract KOPERNIK is an object-oriented database system, that allows uniform specification of database requests and application programs. The user interface is based on Smalltalk, and the object-oriented data model is represented in terms of classes and messages. Techniques are discussed for implementing such a model on top of an underlying relational database system. Those parts of application programs that cannot be translated into a relational language are handled by a Smalltalk processor. The semantics of the database requests is defined in terms of a meta-model and meta-messages, using an object-oriented approach. Hence we derive rules for translation of database requests into SQL queries over a binary relational view, introduced as an intermediate level between the underlying database and our conceptual view.

Permanent object storage and collections for object-oriented systems with rules

The rule-bsaed database and object-oriented paradigms are all relevant to many advanced applications, yet none of the three addresses all of the important issues. In this paper, we discuss the features of a knowledge base management system called TANGUY, which integrates the three paradigms in order to capture the advantages of each. TANGUY provides set-oriented interfaces, data-driven prediction rules, and permanent object storage in the context of a C++-env ironment.

Methods and Tools for Integrating Database Systems and Object-Oriented Programming Systems

The object-oriented paradigm has gained rapid acceptance as the basis for the next generation of database systems. Yet many of the fundamental concepts behind the object-oriented approach are in conflict with the traditional ideas of database management. In this paper we investigate the similarities and differences between the relational database approach and the object-oriented programming language Smalltalk. We develop an object-oriented data model with abstract classes, and discuss the techniques for translating requests into a relational language.

A Deductive Database System with Applications to Route Planning

The issue of deductive query optimization has received widespread attention, yet the problem of dealing with functions defined on complex data structures remains unresolved. In this paper we present an approach which allows for abstract data types and arbitrary user-defined functions within the framework of an extended relational model. Functions may appear in both rules and queries, and the optimization process uses a combination of term rewriting and distribution of selections. Our approach provides a clean integration of functions into both the language and the optimization algorithm, and yields efficient strategies for a wide range of queries. The technique is demonstrated on a route planning application.