A timely survey of the field from the point of view of some of the subject's most active researchers. Divided into several parts organized by theme, the book first covers the underlying methodology regarding active rules, followed by formal specification, rule analysis, performance analysis, and support tools. It then moves on to the implementation of active rules in a number of commercial systems, before concluding with applications and future directions for research. All researchers in databases will find this a valuable overview of the topic.

Inhalt

I Fundamentals.- 1 Introduction.- 1.1 Introduction.- 1.2 Applications.- 1.2.1 Database System Extensions.- 1.2.2 Closed Database Applications.- 1.2.3 Open Database Applications.- 1.2.4 Example Application.- 1.2.5 Conclusions.- 1.3 Knowledge Model.- 1.3.1 Event.- 1.3.2 Condition.- 1.3.3 Action.- 1.4 Execution Model.- 1.5 Management.- 1.6 Conclusion.- 1.7 References.- 2 Architecture of Active Database Systems.- 2.1 Introduction.- 2.2 Degree of Integration.- 2.2.1 Layered Architecture.- 2.2.2 Integrated Architecture.- 2.3 Client-Server Architecture of the Underlying DBMS.- 2.4 Data Model and Programming Language Issues.- 2.5 Rule Specification and Registration.- 2.6 Rule Processing.- 2.6.1 Primitive Event Detector Architecture.- 2.6.2 Composite Event Detector Architecture.- 2.6.3 Event Consumption and Logging.- 2.6.4 Guarded Events, Light-Weight Vs. Heavy-Weight Events.- 2.6.5 Rule Scheduling.- 2.6.6 Transaction Models.- 2.6.7 Rule Execution.- 2.7 Recovery.- 2.8 Conclusion.- 2.9 References.- Advanced Topics.- 3 Rule Analysis.- 3.1 Introduction.- 3.2 Termination Analysis.- 3.2.1 Triggering and Activation Graphs.- 3.2.2 Building the Activation Graph.- 3.2.3 Termination with Priorities.- 3.3 Confluence Analysis.- 3.3.1 Analyzing Commutativity.- 3.3.2 Confluence with Priorities.- 3.4 Conclusion.- 3.5 References.- 4 Optimization.- 4.1 Introduction.- 4.2 Optimizing Single Rules.- 4.2.1 Exploiting Parameters.- 4.2.2 Moving Constraints.- 4.3 Optimizing Multiple Rules.- 4.4 Conclusion.- 4.5 Acknowledgments.- 4.6 References.- 5 Monitoring Complex Rule Conditions.- 5.1 Introduction.- 5.2 Incremental Evaluation Techniques.- 5.3 Differencing Relational Expressions.- 5.4 Monitoring Active Rule Conditions in AMOS.- 5.4.1 Rules in AMOSQL.- 5.4.2 Rule Compilation.- 5.5 Partial Differencing.- 5.5.1 Breadth-First Propagation.- 5.5.2 Differencing Base Relations.- 5.5.3 Partial Differencing of Views.- 5.6 Conclusion.- 5.7 References.- 6 Performance Assessment.- 6.1 Introduction.- 6.2 Performance-Critical Aspects of Active Database Systems.- 6.2.1 Performance of Active Database Applications.- 6.2.2 Performance-Critical Aspects of Active Database Management Systems.- 6.3 Performance Measurement of Active Database Management Systems.- 6.3.1 Benchmark Design.- 6.3.2 Factors and Modes.- 6.3.3 Results for SAMOS.- 6.3.4 Lessons and Observation.- 6.4 Steps Towards Performance Improvement of ADBMS's.- 6.4.1 Optimizing ADBMS Implementations.- 6.4.2 Tuning ADBMS Applications.- 6.5 Related Work.- 6.6 Conclusion.- 6.7 Acknowledgments.- 6.8 References.- 7 Tool Support.- 7.1 Introduction.- 7.2 Analysis and Design Support.- 7.2.1 Graphical Description Tools.- 7.2.2 Validation Tools.- 7.2.3 Verification Tools.- 7.3 Implementation Support.- 7.3.1 Tracing Tools.- 7.4 Maintenance Support.- 7.4.1 Browsers.- 7.4.2 Evolution Support Tools.- 7.4.3 Explanation Tools.- 7.4.4 Measurement Tools.- 7.5 From Isolated Tools to Integrated Environments.- 7.6 Conclusion.- 7.7 References.- 8 ECA Functionality in a Distributed Environment.- 8.1 Introduction.- 8.1.1 Challenges.- 8.1.2 Dimensions Revisited.- 8.1.3 Outline of the Chapter.- 8.2 Two Views of the Networked Active Database System.- 8.3 Applications for ECA Rules in Distributed Environments.- 8.3.1 Service View.- 8.3.2 Communications Channel View.- 8.4 How Distribution Affects the Knowledge Model.- 8.5 How Distribution Affects the Execution Model.- 8.5.1 Architectural Model of the Network System.- 8.5.2 Event Detection.- 8.5.3 Scheduling.- 8.5.4 Condition Evaluation and Action Execution.- 8.6 Classification of Existing Approaches.- 8.7 Conclusion.- 8.8 References.- 9 Comparing Deductive and Active Databases.- 9.1 Introduction.- 9.1.1 Main Classes of Rule-Based Database Systems.- 9.1.2 Some Pragmatic Issues to Confront.- 9.1.3 Possible Directions for Unification Efforts.- 9.1.4 Main Requirements for Unification Efforts.- 9.2 Deductive Rules Compared with Active Rules.- 9.2.1 Semantic Dissimilarities.- 9.2.2 Syntactic Similarities.- 9.2.3 A Dimensional Analysis of Deductive Rule Sets.- 9.3 Bringing Deductive and Active Rules Together.- 9.3.1 Issues and Targets.- 9.3.2 Basic Research Stances.- 9.4 A Brief Survey of Proposals for Languages with Deductive and Active Capabilities.- 9.4.1 The Widom Spectrum.- 9.4.2 DDB-Oriented Proposals.- 9.4.3 ADB-Oriented Proposals.- 9.5 Conclusion.- 9.6 Acknowledgments.- 9.7 References.- III Systems.- 10 Active Database Features in SQL3.- 10.1 Introduction.- 10.2 Triggers in SQL3.- 10.2.1 Constraints in SQL3.- 10.2.2 Overview of SQL3 Triggers.- 10.2.3 Execution Model for Triggers in SQL3.- 10.2.4 Discussion of SQL3's Execution Model.- 10.3 Examples.- 10.4 Comparison of SQL3 Triggers to the Active Database Framework.- 10.4.1 Knowledge Model.- 10.4.2 Execution Model.- 10.4.3 Management.- 10.5 Conclusion.- 10.6 References.- 11 Ariel.- 11.1 Introduction.- 11.2 The Ariel Query and Rule Languages.- 11.2.1 Semantics of Rule Execution.- 11.3 Examples.- 11.4 Architectural Overview.- 11.4.1 The Discrimination Network.- 11.4.2 The Rule Execution Monitor.- 11.5 System Properties and Relationship to Other Work.- 11.6 Conclusion.- 11.7 References.- 12 SAMOS.- 12.1 Introduction.- 12.2 ECA Rules in SAMOS.- 12.3 The SAMOS Prototype.- 12.3.1 Defining Rules and Events.- 12.3.2 Rule Processing.- 12.3.3 Evaluation of the SAMOS Prototype.- 12.3.4 An Example.- 12.4 Future Directions.- 12.5 Conclusion.- 12.6 Acknowledgments.- 12.7 References.- 13 EXACT: An Approach to Coping with Heterogeneous Rule Execution Models.- 13.1 Introduction.- 13.2 The Knowledge Model.- 13.3 The Execution Model.- 13.4 Some Examples.- 13.4.1 Dynamic Display Support.- 13.4.2 Relationship Semantic Support.- 13.4.3 Integrity Constraint Maintenance.- 13.5 Conclusion.- 13.6 References.- 14 REACH.- 14.1 Introduction.- 14.2 The OpenOODB Platform.- 14.3 REACH Goals, Design Principles, and Implementation Decisions.- 14.3.1 Event Detection and Composition.- 14.3.2 Rule Execution and Coupling Modes.- 14.3.3 Events: Scoping, Composition, and Parameter Passing.- 14.4 REACH Environment and Tools.- 14.4.1 Modeling Rules with OMT+.- 14.4.2 Rule Language REAL.- 14.4.3 Administration Tools.- 14.5 Summary of Features.- 14.6 Conclusion.- 14.7 Acknowledgments.- 14.8 References.- 15 NAOS.- 15.1 Introduction.- 15.2 Rules in NAOS.- 15.2.1 Rules and O2.- 15.2.2 Rule Definition.- 15.2.3 Event Part.- 15.2.4 Condition.- 15.2.5 Action.- 15.2.6 Event-Condition-Action Binding.- 15.2.7 Management of Rules.- 15.2.8 Conclusion.- 15.3 Event Types.- 15.3.1 Primitive Event Types.- 15.3.2 Composite Event Types.- 15.3.3 Validity Time Interval.- 15.3.4 With Clause.- 15.4 Rule Execution.- 15.4.1 Coupling Modes.- 15.4.2 Multiple Rule Execution.- 15.4.3 Cascading Execution.- 15.4.4 Net Effect Policy and Error Handling.- 15.4.4 Asynchronous Rule Execution.- 15.4.5 Conclusion.- 15.5 Implementation.- 15.5.1 Analyser.- 15.5.2 Constructor.- 15.5.3 Event Detectors and Event Manager.- 15.5.4 Executor.- 15.6 Conclusion.- 15.7 Acknowledgments.- 15.8 References.- 16 PFL: An Active Functional DBPL.- 16.1 Introduction.- 16.2 PFL.- 16.2.1 Types.- 16.2.2 Expressions and Functions.- 16.2.3 Bulk Data.- 16.2.4 Queries and Transactions.- 16.2.5 User-Defined Events.- 16.3 The Active Subsystem.- 16.3.1 Primitive Events.- 16.3.2 ECA rules.- 16.3.3 Execution Model.- 16.3.4 Abort Handling.- 16.4 Conclusion.- 16.5 Acknowledgments.- 16.6 References.- 17 Chimera: A Langu…