Management of Heterogeneous and Autonomous Database Systems

Management of Heterogeneous and Autonomous Database Systems

Edited by

Ahmed Elmagarmid Marek Rusinkiewicz Amit Sheth

Morgan Kaufmann Publishers, Inc. San Francisco, California

Contents Preface

xiii

1 An Overview of Multidatabase Systems: Past and Present Athman Bouguettaya, Boualern Benatallah, and Ahmed Elmagarmid 1.1 Terminology 1.1.1 Distribution. 1.1.2 Heterogeneity 1.1.3 Autonomy 1.1.4 Interoperability ; 1.2 Architecture of Heterogeneous Distributed Databases 1.2.1 Global Schema Integration 1.2.2 Federated Database Systems (FDBSs) 1.2.3 Multidatabase Language Approach 1.3 Research Issues in Multidatabase Systems 1.3.1 Schema and Language Translation 1.3.2 Schema Integration 1.3.3 Multidatabase Consistency and Dependencies - 1.3.4 Workflow Management Systems 1.3.5 Transaction Processing 1.4 Multidatabase Prototypes 1.5 Summary Bibliography 2 Local Autonomy and Its Effects on Multidatabase Systems Ahmed Elmagarmid, Weimin Du, and Rafi Ahmed 2.1 Schema Integration 2.1.1 Heterogeneous Data Models 2.1.2 Resolution ofjkhematic Discrepancies 2.1.3 Reconciliation of Data Values 2.1.4 Query and Update Translation 2.2 Query Processing 2.2.1 Unification Decomposition

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viii

Contents 2.2.2 Optimization 2.3 Transaction Management 2.3.1 Concurrency Control 2.3.2 Commitment and Recovery 2.3.3 Replication Control 2.4 Summary Bibliography

3 Semantic Similarities Between Objects in Multiple Databases Vipul Kashyap and Amit Sheth 3.1 Semantics: Perspectives and Representation 3.1.1 Context: The Semantic Component 3.1.2 Abstractions/Mappings: The Structural Component . . 3.1.3 Modeling Uncertainty, Inconsistency, and Incompleteness 3.2 Semantic Proximity: A Model for Representing Semantic Similarities 3.2.1 Context(s) of the Two Objects: The Semantic Component 3.2.2 Issues of Representation and Reasoning 3.2.3 The Vocabulary Problem 3.2.4 The Structural Components 3.2.5 Modeling Uncertainty: Fuzzy Strengths as a Function of Semantic Proximity 3.2.6 A Semantic Classification of Object Similarities 3.3 Context Building Approach 3.3.1 Context-Dependent Interpretation 3.3.2 Context Management Using a Truth Maintenance System 3.3.3 Discussion 3.4 Context Interchange Approach 3.4.1 Context and Metadata 3.4.2 Data Conversion (Conversion Functions) 3.4.3 Discussion 3.5 Common Concepts: An Approach to Determine Attribute Similarities 3.5.1 Representation of Attribute Semantics by Common Concepts 3.5.2 Establishing Attribute Relationships 3.5.3 Discussion 3.6 Semantic Abstractions Approach 3.6.1 The Semantic Enrichment Phase 3.6.2 The Detection Phase 3.6.3 Discussion 3.7 Semantic Similarity Based on Fuzzy Knowledge 3.7.1 Terminological Knowledge

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Contents

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3.7.2 Semantic Similarity of Classes 3.7.3 Discussion 3.8 Related Work Bibliography

83 85 85 85

Resolution of Representational Diversity in Multidatabase Systems

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Joachim Hammer and Dennis McLeod 4.1 Related Research 4.2 Heterogeneity in a Collaborative Sharing Environment 4.2.1 A Spectrum of Representational Heterogeneities . . . . 4.2.2 Causes of Representational Diversities 4.3 Remote-Exchange Architecture 4.3.1 Core Object Data Model 4.3.2 Remote Sharing Language 4.3.3 Local Lexicon . . . .