The Experts below are selected from a list of 65922 Experts worldwide ranked by ideXlab platform
Jennifer Widom - One of the best experts on this subject based on the ideXlab platform.
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an algebraic approach to static analysis of Active Database rules
ACM Transactions on Database Systems, 2000Co-Authors: Elena Baralis, Jennifer WidomAbstract:Rules in Active Database systems can be very difficult to program due to the unstructured and unpredictable nature of rule processing. We provide static analysis techniques for predicting whether a given rule set is guaranteed to terminate and whether rule execution is confluent (guaranteed to have a unique final state). Our methods are based on previous techniques for analyzing rules in Active Database systems. We improve considerably on the previous techniques by providing analysis criteria that are much less conservative: our methods often determine that a rule set will terminate or is confluent when previous methods could not make this determination. Our improved analysis is based on a “propagation” algorithm, which uses an extended relational algebra to accurately determine when the action of one rule can affect the condition of another, and determine when rule actions commute. We consider both conditon-action rules and event-condition-action-rules, making our approach widely applicable to relational Active Database rule languages and to the trigger language in the SQL:1999 standard.
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the starburst Active Database rule system
IEEE Transactions on Knowledge and Data Engineering, 1996Co-Authors: Jennifer WidomAbstract:The paper describes the development of the Starburst Rule System, an Active Database rules facility integrated into the Starburst extensible relational Database system at the IBM Almaden Research Center. The Starburst rule language is based on arbitrary Database state transitions rather than tuple or statement level changes, yielding a clear and flexible execution semantics. The rule system has been implemented completely. Its rapid implementation was facilitated by the extensibility features of Starburst, and rule management and rule processing are integrated into all aspects of Database processing.
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static analysis techniques for predicting the behavior of Active Database rules
ACM Transactions on Database Systems, 1995Co-Authors: Alex Aiken, Joseph M Hellerstein, Jennifer WidomAbstract:This article gives methods for statically analyzing sets of Active Database rules to determine if the rules are (1) guaranteed to terminate, (2) guaranteed to produce a unique final Database state, and (3) guaranteed to produce a unique stream of observable actions. If the analysis determines that one of these properties is not guaranteed, it isolates the rules responsible for the problem and determines criteria that, if satisfied, guarantee the property. The analysis methods are presented in the context of the Starburst Rule System.
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Active Database systems
Modern database systems, 1995Co-Authors: Umeshwar Dayal, Eric N Hanson, Jennifer WidomAbstract:Integrating a production rules facility into a Database system provides a uniform mechanism for a number of advanced Database features including integrity constraint enforcement, derived data maintenance, triggers, alerters, protection, version control, and others. In addition, a Database system with rule processing capabilities provides a useful platform for large and effcient knowledge-base and expert systems. Database systems with production rules are referred to as Active Database systems, and the of Active Database systems has indeed been Active. This chapter summarizes current work in Active Database systems; topics covered include Active Database rule models and languages, rule execution semantics, and implementation issues. 0
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Active Database systems triggers and rules for advanced Database processing
1994Co-Authors: Umeshwar Dayal, Jennifer Widom, Stefano CeriAbstract:From the Publisher: Active Database systems enhance traditional Database functionality with powerful rule-processing capabilities, providing a uniform and efficient mechanism for many Database system applications. Among these applications are integrity constraints, views, authorization, statistics gathering, monitoring and alerting, knowledge-based systems, expert systems, and workflow management. This significant collection focuses on the most prominent research projects in Active Database systems. The project leaders for each prototype system provide detailed discussions of their projects and the relevance of their results to the future of Active Database systems. Features: A broad overview of current Active Database systems and how they can be extended and improved A comprehensive introduction to the core topics of the field, including its motivation and history Coverage of Active Database (trigger) capabilities in commercial products Discussion of forthcoming standards
Stella Gatziu - One of the best experts on this subject based on the ideXlab platform.
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investigating termination in Active Database systems with expressive rule languages
Lecture Notes in Computer Science, 1997Co-Authors: Anca Vaduva, Stella Gatziu, Klaus R. DittrichAbstract:The powerful functionality that Active mechanisms add to Database management systems presents, besides many advantages, a number of problems related to the control of their behavior. This paper deals with one of these problems: the termination of rule execution. We explain the termination aspect and the aim of termination analysis. Then, we present our approach for investigating the termination of rule execution. In contrast to others, this approach also addresses expressive rule languages as they have been proposed for various recent Active Database management system prototypes.
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the Active Database management system manifesto a rulebase of adbms features
RIDS '95 Proceedings of the Second International Workshop on Rules in Database Systems, 1995Co-Authors: Klaus R. Dittrich, Stella Gatziu, Andreas GeppertAbstract:Active Database systems have been a hot research topic for quite some years now. However, while "Active functionality" has been claimed for many systems, and notions such as "Active objects" or "events" are used in many research areas (even be- yond Database technology), it is not yet clear which functionality a Database manage- ment system must support in order to be legitimately considered as an Active system. In this paper, we attempt to clarify the notion of "Active Database management system" as well as the functionality it has to support. We thereby distinguish mandatory features that are needed to qualify as an Active Database system, and desired features which are nice to have. Finally, we perform a classification of applications of Active Database sys- tems and identify the requirements for an Active Database management system in order to be applicable in these application areas.
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a designer s benchmark for Active Database management systems oo7 meets the beast
RIDS '95 Proceedings of the Second International Workshop on Rules in Database Systems, 1995Co-Authors: Andreas Geppert, Stella Gatziu, Klaus R. DittrichAbstract:A benchmark for Active Database management systems is described. We are particularly interested in performance tests that help to identify performant and inefficient components. Active functionality that is relevant with respect to performance is identified, and a series of tests is designed that measure the efficiency of the performance- critical components. Results obtained from running the benchmark for a concrete system are presented.
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a designer s benchmark for Active Database management systems 007meets the beast
A Designer''s Benchmark for Active Database management Systems: 007Meets the BEAST, 1995Co-Authors: A Geppert, Stella Gatziu, K R DittrichAbstract:A benchmark for Active Database management systems is described. We are particularly interested in performance tests that help to identify performant and inefficient components. Active functionality that is relevant with respect to performance is identified, and a series of tests is designed that measure the efficiency of the performance- critical components. Results obtained from running the benchmark for a concrete system are presented.
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detecting composite events in Active Database systems using petri nets
International Workshop on Research Issues in Data Engineering, 1994Co-Authors: Stella Gatziu, K R DittrichAbstract:The detection of events in an Active Database system turns out to be a difficult problem due to the expressive event specification languages proposed in the recent past which include, among others, complexly defined events (composite events). Therefore, a mechanism is required that is suitable to model the semantics of composite events and to implement the event detector. We demonstrate how Petri nets can be used as the basis of such a mechanism in the context of the SAMOS Active Database system prototype. >
Klaus R. Dittrich - One of the best experts on this subject based on the ideXlab platform.
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investigating termination in Active Database systems with expressive rule languages
Lecture Notes in Computer Science, 1997Co-Authors: Anca Vaduva, Stella Gatziu, Klaus R. DittrichAbstract:The powerful functionality that Active mechanisms add to Database management systems presents, besides many advantages, a number of problems related to the control of their behavior. This paper deals with one of these problems: the termination of rule execution. We explain the termination aspect and the aim of termination analysis. Then, we present our approach for investigating the termination of rule execution. In contrast to others, this approach also addresses expressive rule languages as they have been proposed for various recent Active Database management system prototypes.
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the Active Database management system manifesto a rulebase of adbms features
RIDS '95 Proceedings of the Second International Workshop on Rules in Database Systems, 1995Co-Authors: Klaus R. Dittrich, Stella Gatziu, Andreas GeppertAbstract:Active Database systems have been a hot research topic for quite some years now. However, while "Active functionality" has been claimed for many systems, and notions such as "Active objects" or "events" are used in many research areas (even be- yond Database technology), it is not yet clear which functionality a Database manage- ment system must support in order to be legitimately considered as an Active system. In this paper, we attempt to clarify the notion of "Active Database management system" as well as the functionality it has to support. We thereby distinguish mandatory features that are needed to qualify as an Active Database system, and desired features which are nice to have. Finally, we perform a classification of applications of Active Database sys- tems and identify the requirements for an Active Database management system in order to be applicable in these application areas.
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a designer s benchmark for Active Database management systems oo7 meets the beast
RIDS '95 Proceedings of the Second International Workshop on Rules in Database Systems, 1995Co-Authors: Andreas Geppert, Stella Gatziu, Klaus R. DittrichAbstract:A benchmark for Active Database management systems is described. We are particularly interested in performance tests that help to identify performant and inefficient components. Active functionality that is relevant with respect to performance is identified, and a series of tests is designed that measure the efficiency of the performance- critical components. Results obtained from running the benchmark for a concrete system are presented.
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integrating Active concepts into an object oriented Database system
Database Programming Languages, 1992Co-Authors: Stella Gatziu, Andreas Geppert, Klaus R. DittrichAbstract:This paper describes the Active, object-oriented Database system SAMOS being developed as a research prototype. Its main approach is the integration of rules in the sense of Active Database systems into a general object-oriented data model. Our effort is also focussed on integrating the rule system with transaction processing in a meaningful way.
K R Dittrich - One of the best experts on this subject based on the ideXlab platform.
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a designer s benchmark for Active Database management systems 007meets the beast
A Designer''s Benchmark for Active Database management Systems: 007Meets the BEAST, 1995Co-Authors: A Geppert, Stella Gatziu, K R DittrichAbstract:A benchmark for Active Database management systems is described. We are particularly interested in performance tests that help to identify performant and inefficient components. Active functionality that is relevant with respect to performance is identified, and a series of tests is designed that measure the efficiency of the performance- critical components. Results obtained from running the benchmark for a concrete system are presented.
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detecting composite events in Active Database systems using petri nets
International Workshop on Research Issues in Data Engineering, 1994Co-Authors: Stella Gatziu, K R DittrichAbstract:The detection of events in an Active Database system turns out to be a difficult problem due to the expressive event specification languages proposed in the recent past which include, among others, complexly defined events (composite events). Therefore, a mechanism is required that is suitable to model the semantics of composite events and to implement the event detector. We demonstrate how Petri nets can be used as the basis of such a mechanism in the context of the SAMOS Active Database system prototype. >
Rainer Unland - One of the best experts on this subject based on the ideXlab platform.
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on the semantics of complex events in Active Database management systems
International Conference on Data Engineering, 1999Co-Authors: Detlef Zimmer, Rainer UnlandAbstract:Active Database management systems have been developed for applications needing an automatic reaction in response to certain events. Events can be simple in nature or complex. Complex events rely on simpler ones and are usually specified with the help of operators of an event algebra. There are quite a few papers dealing with extensions of existing event algebras. However, a systematic and comprehensive analysis of the semantics of complex events is still lacking. As a consequence most proposals suffer from different kinds of peculiarities. Independent aspects are not treated independently, leading to shady mixtures of aspects in operators. Moreover, aspects are not always treated uniformly. Operators may have other semantics than expected. The paper addresses these problems by an extensive and in-depth analysis of the foundations of complex events. As a result of this analysis, a (formal) meta-model for event algebras is introduced that subdivides the semantics of complex events into elementary, independent dimensions. Each of these dimensions are discussed in detail. The resulting language specification fulfils the criteria for a good language design (like orthogonality, symmetry, homogeneity, lean set of language constructs) to a large extent.
