Abstract
The concept of a trigger is central to any active database. Upon the occurrence of a trigger event, the trigger is “fired”, i.e, the trigger action is executed. We describe a model and a language for specifying basic and composite trigger events in the context of an object-oriented database. The specified events can be detected efficiently using finite automata.
We integrate our model with O++, the database programming language for the ode object database being developed at AT&T Bell Labs. We propose a new Event-Action model, which folds into the event specification the condition part of the well-known Event-Condition-Action model and avoids the multiple coupling modes between the event, condition, and action trigger components.
- 1 R. Agrawal and N. H. Gehani, "Ode (Object Database and Environment): The Language and the Data Model", Prec. ACM-SIGMOD 1989 lnt'l Conf. Management of Data, Portland, Oregon, May-June 1989, 36-45. Google ScholarDigital Library
- 2 C. Beeri and T. Mile, "A Model for Active Object Oriented Database", Prec. of the 17th {nt'l Conf. on Very Large Databases, Barcelona, Spain, Sept. 1991, 337-349. Google ScholarDigital Library
- 3 R. H. Campbell and A. N. Habermann, "The Specification of Process Synchronization by Path Expressions", in Lecture Notes in Computer Science, vol. 16, Springer-Vedag, 1974. Google ScholarDigital Library
- 4 R. H. Campbell and A. N. Habermann, "Path Expressions in Pascal", Proceedings of the Fourth International Conference on Software Engineering, 1979,212-219. Google ScholarDigital Library
- 5 S. Chakravarthy and D. Mishra, "An Event Specification Language (Snoop) for Active Databases and its Detection", University of Florida CIS Tech. Rep.-91-23, September 1991.Google Scholar
- 6 U. Dayal, B. Blaustein, A. Buchmann, U. Chakravarthy, M. Hsu, R. Ladin, D. McCarthy, A. Rosenthal, S. Satin, M. J. Carey, M. Livny and R. Jauhad, "The HiPAC Project: Combining Active Databases and Timing Constraints", ACM-SIGMOD Record 17, 1 (March 1988), 51-70. Google ScholarDigital Library
- 7 U. Dayal, M. Hsu and R. Ladin, "A Transaction Model for Long-Running Activities", Prec. of the 17th Int'l Conf. on Very Large Databases, Barcelona, Spain, Sept. 1991, 113-122. Google ScholarDigital Library
- 8 N.H. Gehani and H. V. Jagadish, "Ode as an Active Database: Constraints and Triggers", Prec. 17th Int'l Conf. Very Large Data Bases, Barcelona, Spain, 1991, 327-336. Google ScholarDigital Library
- 9 N. H. Gehani, H. V. Jagadish and O. Shmueli, Composite Event Specification in Active Databases: Model & Implementation, AT&T Bell Laboratories, 1992.Google Scholar
- 10 N. H. Gehani, H. V. Jagadish and O. Shmueli, "Event Specification in an Active Object-Oriented Database", AT&T Bell Labs Technical Memorandum, 1992.Google Scholar
- 11 D. Hard, "Statecharts: A Visual Formalism forConaplex Systems", Science of Computer Programming 8, (1988), 231-274. Google ScholarDigital Library
- 12 M.R. Headington and A. E. Oldehoeft, "Open Predicate Path Expressions and their Implementation in Highly Parallel Computing Environments", Proceedings of the International Conference on Parallel Processing, 1985, 239-246.Google Scholar
- 13 R. Hull and D. Jacobs, "Language Constructs for Programming Active Databases", Prec. of the 17th Int' 1 Conf. on Very Large Databases, Barcelona, Spain, Sept. 1991. Google ScholarDigital Library
- 14 S. N. Khoshafian and G. P. Copeland, "Object Identity", Prec. OOPSLA '86, Pordand, Oregon, Sept. 1986, 406-416. Google ScholarDigital Library
- 15 G. M. Lehman, B. Lindsay, H. Pirahesh and K. B. Schiefer, "Extensions to Starburst: Objects, Types, Functions, and Rules", Comm. ACM 34, 10 (October 1991), 94-109. Google ScholarDigital Library
- 16 D.R. McCarthy and U. Dayal, "The Architecture of An Active Database Management System", Prec. ACM- SIGMOD 1989 Int'l Conf. Management of Data, Portland, Oregon, May-June 1989, 215-224. Google ScholarDigital Library
- 17 J. Melton, (ed.), "fISO-ANSI Working Draft) Database Language SQL2 and SQL3", ANSI X3H2-90-001, Dec. 1989.Google Scholar
- 18 A. Silberschatz, M. Stonebraker and J. Ullman, "Database Systems: Achievements and ~rmnities", Comm. ACM 34, 10 (October 1991), 110-120. Google ScholarDigital Library
- 19 A. Skarra, "Concurrency Control for Cooperating Transactions in an Object Oriented Database", SIGPLAN Notices Notices 24, 4 (April. 1989),. Google ScholarDigital Library
- 20 M. Stonebraker and G. Kemnitz, "The POSTGRES Next-Generation Database Management System", Comm. ACM 34, I0 (October 1991), 78-93. Google ScholarDigital Library
Index Terms
- Event specification in an active object-oriented database
Recommendations
Event specification in an active object-oriented database
SIGMOD '92: Proceedings of the 1992 ACM SIGMOD international conference on Management of dataThe concept of a trigger is central to any active database. Upon the occurrence of a trigger event, the trigger is “fired”, i.e, the trigger action is executed. We describe a model and a language for specifying basic and composite trigger events in the ...
The Ode Active Database: Trigger Semantics and Implementation
ICDE '96: Proceedings of the Twelfth International Conference on Data EngineeringTriggers are the basic ingredient of active databases. Ode triggers are event-action pairs. An event can be a composite event (i.e., an event composed from other events). Composite events are detected by translating the event specifications into finite ...
Parallel Event Detection in Active Database Systems: The Heart of the Matter
ARTDB '97: Proceedings of the Second International Workshop on Active, Real-Time, and Temporal Database SystemsThis paper proposes a strategy for parallel composite event detection in active database management systems. Up to now, event detection is sequential and totally synchronized, and thus preserves the timely order of events during the detection process. ...
Comments