Results 1 - 10 of 47

The Starburst active database rule system

by Jennifer Widom - IEEE TKDE , 1996
"... This paper describes our development of the Starburst Rule System, an active database rules facility integrated into the Starburst extensible relational database sys-tem at the IBM Almaden Research Center. The Starburst rule language is based on arbitrary database state transitions rather than tuple ..."
Abstract - Cited by 56 (0 self) - Add to MetaCart
This paper describes our development of the Starburst Rule System, an active database rules facility integrated into the Starburst extensible relational database sys-tem at the IBM Almaden Research Center. The Starburst rule language is based on arbitrary database state transitions rather than tuple- or statement-level changes, yield-ing a clear and exible 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 is integrated into all aspects of database processing. Index terms: active database systems, database production rules, extensible database systems, expert database systems 1
(Show Context)

Efficient Maintenance of Materialized Mediated Views

by James Lu, Guido Moerkotte, Joachim Schü, V. S. Subrahmanian - In SIGMOD , 1995
"... Integrating data and knowledge from multiple heterogeneous sources --- like databases, knowledge bases or specific software packages --- is often required for answering certain queries. Recently, a powerful framework for defining mediated views spanning multiple knowledge bases by a set of constr ..."
Abstract - Cited by 55 (8 self) - Add to MetaCart
Integrating data and knowledge from multiple heterogeneous sources --- like databases, knowledge bases or specific software packages --- is often required for answering certain queries. Recently, a powerful framework for defining mediated views spanning multiple knowledge bases by a set of constrained rules (cf. work of Kanellakis et. al. [27]) was proposed [39, 5, 26]. Within this paper, we investigate the materialization of these views by unfolding the view definition and the efficient maintenance of the resulting materialized mediated view in case of updates. Thereby, we consider two kinds of updates: updates to the view and updates to the underlying sources. For each of these two cases several efficient algorithms maintaining materialized mediated views are given. We improve on previous algorithms like the DRed algorithm [22] and introduce a new fixpoint operator WP which --- opposed to the standard fixpoint operator TP [19] --- allows us to correctly capture the update'...
(Show Context)

Deductive and Active Databases: Two Paradigms or Ends of a Spectrum?

by Jennifer Widom - Proc. 1st Int. Workshop on Rules in Database Systems , 1994
"... This position paper considers several existing relational database rule languages with a focus on exploring the fundamental differences between deductive and active databases. We find that deductive and active databases do not form two discernible classes, but rather they delineate two ends of a spe ..."
Abstract - Cited by 24 (0 self) - Add to MetaCart
This position paper considers several existing relational database rule languages with a focus on exploring the fundamental differences between deductive and active databases. We find that deductive and active databases do not form two discernible classes, but rather they delineate two ends of a spectrum of database rule languages. We claim that this spectrum also corresponds to a notion of abstraction level, with deductive rule languages at a higher level and active rule languages at a lower level. 1 Introduction Research on incorporating rule processing into database systems historically has been divided into two distinct areas: deductive databases and active databases. In deductive databases, logic programming style rules are used to provide a more powerful user interface than that provided by most database query languages [CGT90, Ull89]. In active databases, production style rules are used to provide automatic execution of database operations in response to certain events and/or c...
(Show Context)

The Starburst Rule System: Language design, implementation, and applications

by Jennifer Widom - IEEE Data Engineering Bulletin, Special Issue on Active Databases , 1992
"... This short paper provides an overview of the Starburst Rule System, a production rules facility inte-grated into the Starburst extensible database system. The rule language is based on arbitrary database state transitions rather than tuple- or statement-level changes, yielding a clear and exible ex ..."
Abstract - Cited by 24 (3 self) - Add to MetaCart
This short paper provides an overview of the Starburst Rule System, a production rules facility inte-grated into the Starburst extensible database system. The rule language is based on arbitrary database state transitions rather than tuple- or statement-level changes, yielding a clear and exible execution semantics. The rule system was implemented rapidly using the extensibility features of Starburst; it is integrated into all aspects of query and transaction processing, including concurrency control, autho-rization, recovery, etc. Using the Starburst Rule System, we have developed a number of methods for automatically generating database rule applications, including integrity constraints, materialized views, deductive rules, and semantic heterogeneity. 1

Active Databases and Agent Systems - A Comparison

by James Bailey, Michael Georgeff, David Kemp, David Kinny, Kotagiri Ramamohanarao , 1995
"... This paper examines Active Databases and Agent Systems, comparing their purpose, structure, functionality, and implementation. Our presentation is aimed primarily at an audience familiar with active database technology. We show that they draw upon very similar paradigms in their quest to supply reac ..."
Abstract - Cited by 22 (3 self) - Add to MetaCart
This paper examines Active Databases and Agent Systems, comparing their purpose, structure, functionality, and implementation. Our presentation is aimed primarily at an audience familiar with active database technology. We show that they draw upon very similar paradigms in their quest to supply reactivity. This presents opportunities for migration of techniques and formalisms between the two fields. 1 fjbailey,kemp,dnk,raog@cs.mu.oz.au 2 georgeff@aaii.oz.au 3 Appears in T.Sellis, editor, Proceedings of the Second International Workshop on Rules in Database Systems, Lecture Notes in Computer Science 985, pages 342-356, Athens, Greece, 1995. 1 Introduction In recent times, two technologies have become prominent in the database and artificial intelligence research communities. An Active Database (ADB) is a system which supplements traditional database functionality by reacting automatically to state changes, both internal and external, without user intervention. An Agent System (A...

Processing Production Rules in DEVICE, an Active Knowledge Base System

by Nick Bassiliades, Ioannis Vlahavas - DATA & KNOWLEDGE ENGINEERING , 1997
"... Production rules are useful for several tasks of active database systems, such as integrity constraint checking, derived data maintenance, database state monitoring, etc. Furthermore production rules can express knowledge in a high-level form for problem solving in Knowledge Base Systems (KBS). Pres ..."
Abstract - Cited by 16 (15 self) - Add to MetaCart
Production rules are useful for several tasks of active database systems, such as integrity constraint checking, derived data maintenance, database state monitoring, etc. Furthermore production rules can express knowledge in a high-level form for problem solving in Knowledge Base Systems (KBS). Present active object-oriented database (OODB) systems traditionally provide event-driven rules which are triggered by events, i.e. database modifications. This paper describes DEVICE, a high-level rule integration scheme into an active OODB system, resulting in an active KBS. The paper emphasises on the run-time processing of production rules, namely the incremental matching of rule conditions, as well as rule selection and firing. The matching of production rules requires special algorithms based on the flow of updated data through a discrimination network, like RETE, TREAT, etc. DEVICE offers a smooth integration of production rules into an active OODB system that only supports event-driven rules, without introducing new data structures, maintaining at the same time the properties of discrimination networks. This is achieved using complex events to map the conditions of production rules and monitor the database to incrementally match those conditions. DEVICE maps each production rule into one event-driven rule that is easy to maintain and offers centralised rule selection control for correct run-time behaviour and conflict resolution. Furthermore, DEVICE provides the infrastructure for the integration of various other rule paradigms into a single KBS, like deductive rules and integrity constraints and leaves room for the optimisation of the matching process through variations of the basic discrimination network.
(Show Context)

DEVICE: Compiling Production Rules into Event-Driven Rules Using Complex Events

by Nick Bassiliades, Ioannis Vlahavas - INFORMATION AND SOFTWARE TECHNOLOGY , 1997
"... This paper describes a technique for the smooth integration of production rules into an active Object-Oriented Database (OODB) system that provides Event-Condition-Action (ECA) rules only, called DEVICE. The emphasis is given on the compilation of rule conditions into a discrimination network for in ..."
Abstract - Cited by 15 (8 self) - Add to MetaCart
This paper describes a technique for the smooth integration of production rules into an active Object-Oriented Database (OODB) system that provides Event-Condition-Action (ECA) rules only, called DEVICE. The emphasis is given on the compilation of rule conditions into a discrimination network for incremental matching at run-time. The network consists of primitive, logical and complex events, that save information about partial condition element matching, as in RETE algorithm and triggers one ECA rule that corresponds to the production rule. The DEVICE method re-uses the primitives of active OODB systems, without introducing low-level data structures and provides an infrastructure for the integration of all database rule paradigms into a single knowledge base system.
(Show Context)

E-DEVICE: An Extensible Active Knowledge Base System with Multiple Rule Type Support

by Nick Bassiliades, Ioannis Vlahavas, Ahmed K. Elmagarmid , 2000
"... This paper describes E-DEVICE, an extensible active knowledge base system (KBS) that supports the processing of event-driven, production, and deductive rules into the same active OODB system. E-DEVICE provides the infrastructure for the smooth integration of various declarative rule types, such as p ..."
Abstract - Cited by 14 (8 self) - Add to MetaCart
This paper describes E-DEVICE, an extensible active knowledge base system (KBS) that supports the processing of event-driven, production, and deductive rules into the same active OODB system. E-DEVICE provides the infrastructure for the smooth integration of various declarative rule types, such as production and deductive rules, into an active OODB system that supports low-level event-driven rules only by a) mapping each declarative rule into one event-driven rule, offering centralized rule selection control for correct run-time behavior and conflict resolution, and b) using complex events to map the conditions of declarative rules and monitor the database to incrementally match those conditions. E-DEVICE provides the infrastructure for easily extending the system by adding a) new rule types as subtypes of existing ones and b) transparent optimizations to the rule matching network. The resulting system is a flexible, yet efficient, KBS that gives the user the ability to express knowledge in a variety of high-level forms for advanced problem solving in data intensive applications.

Efficient maintenance techniques for views over active documents

by Serge Abiteboul, Pierre Bourhis, Bogdan Marinoiu, Ens Cachan - In International Conference on Extending Database Technology (EDBT , 2009
"... Many Web applications are based on dynamic interactions between Web components exchanging flows of information. Such a situation arises for instance in mashup systems or when monitoring distributed autonomous systems. Our work is in this challenging context that has generated recently a lot of atten ..."
Abstract - Cited by 14 (4 self) - Add to MetaCart
Many Web applications are based on dynamic interactions between Web components exchanging flows of information. Such a situation arises for instance in mashup systems or when monitoring distributed autonomous systems. Our work is in this challenging context that has generated recently a lot of attention; see Web 2.0. We introduce the axlog formal model for capturing such interactions and show how this model can be supported efficiently. The central component is the axlog widget defined by one tree-pattern query or more, over an active document (in the Active XML style) that includes some input streams of updates. A widget generates a stream of updates for each query, the updates that are needed to maintain the view corresponding to the query. We exploit an array of known technologies: datalog optimization techniques such as Differential or MagicSet, constraint query languages, and efficient XML filtering (YFilter). The novel optimization technique we propose is based on fundamental new notions: a relevance (different than that of MagicSet), satisfiability and provenance for active documents. We briefly discuss an implementation of an axlog engine, an application that we used to test the approach, and results of experiments. 1.
(Show Context)

Alchemy: Transmuting Base Alloy Specifications into Implementations

by Shriram Krishnamurthi, Daniel J. Dougherty, Kathi Fisler, Daniel Yoo - FSE , 2008
"... Alloy specifications are used to define lightweight models of systems. We present Alchemy, which compiles Alloy specifications into implementations that execute against persistent databases. Alchemy translates a subset of Alloy predicates into imperative update operations, and it converts facts into ..."
Abstract - Cited by 12 (2 self) - Add to MetaCart
Alloy specifications are used to define lightweight models of systems. We present Alchemy, which compiles Alloy specifications into implementations that execute against persistent databases. Alchemy translates a subset of Alloy predicates into imperative update operations, and it converts facts into database integrity constraints that it maintains automatically in the face of these imperative actions. In addition to presenting the semantics and an algorithm for this compilation, we present the tool and outline its application to a non-trivial specification. We also discuss lessons learned about the relationship between Alloy specifications and imperative implementations.