U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings of the 17th International Conference on Very Large Data Bases (VLDB), pages 469--478, September 1991.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....to provide e#cient implementation. Despite the conceptual generality, rules have been so far supported in a fairly restricted form in practical systems (e.g. by built in triggers in relational database management systems such as Oracle, Sybase, and Informix) Active queries, introduced in Alert [37], are more sophisticated than database triggers, since they can be defined on multiple tables, on views, and can be nested within other active queries. However, active queries rely heavily on a number of extensions specific to the IBM Starburst DBMS [14] Compared to the state of art of research ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

.... and join operators in the relational algebra) which serve as the basic building blocks for manipulating data (i.e. relations that are sets of records) In object relational database systems, ADT functions are either represented as expressions [9] or as joins involving virtual relations [10]. 2 When an expression containing an ADT function is evaluated, a (local) function is called to obtain its 1 Embedding a database server on a device is realistic. All major database vendors propose database servers for palm sized PCs, which represent the processing capabilities that we can ....

U. Schreierf et al., "Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS," VLDB, 1991, pp. 469--78.

....are insertions and or deletions from the view predicate associated with the alerter. Again, incremental evaluation may be a reasonable alternative to evaluate the view associated with the alerter. Active Rules The concept of a trigger is also central to active databases [WC96, GJS92, BA93, BM91, SPAM91] which monitor happenings of events for reasons such as authorization checking, general integrity maintenance, alerting, real time application support, workflow management support and so on. Active rules are a very powerful modeling mechanism and, as discussed above, active rules can be used to ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceeding of the 17th International Conference on Very Large Data Bases, pages 469--478, 1991.

....of the evaluation of event expressions have not been reported in any of the works. ffl All of the above three works have been conducted in an object oriented database framework [GJS92b, GD93, CAM93] A number of event specification languages have been defined in the relational database framework [SPAM91, WCL91] but the operators supported in these languages are very limited. In fact, composite CHAPTER 3. ACTIVE AND TEMPORAL DATABASES 59 event specification in the relational and temporal database framework has not been investigated. 3.5 Temporal Logic Temporal Logic (TL) Eme90] was introduced ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive DBMS into an active DBMS. In Proceedings of the 17th International Conference on Very Large Data Bases, pages 469--478, 1991.

....system properties in the Internet) Conquer bridges this gap. Active Databases: Event Condition Action (ECA) systems are rule based programs in which an event triggers the testing of a condition, which in turn (if true) triggers an action. Most of active database systems [28] provide facilities [3, 21, 24, 7, 26, 9, 5] that support ECA rules referring to actions and events such as changes of database state. Some popular active database research prototypes include HiPAC [5] ODE [7] Postgres [26] Starburst [9] These systems support powerful rules and allow very general events, conditions, and actions, and ....

....therefore are difficult to implement efficiently. The result is fairly restricted implementations in practice. For example, typical built in triggers [11] in relational database management systems such as Oracle, Sybase, and Informix usually support only table. Active queries, introduced in Alert [24], are more sophisticated than database triggers, since they can be defined 20 on multiple tables, on views, and can be nested within other active queries. However, active queries rely heavily on a number of extensions specific to the IBM Starburst DBMS [9] Comparing with the state of art of ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

....system properties in the Internet) Conquer bridges this gap. Active Databases: Event Condition Action (ECA) systems are rule based programs in which an event triggers the testing of a condition, which in turn (if true) triggers an action. Most of active database systems [29] provide facilities [3, 21, 24, 7, 26, 9, 5] that support ECA rules referring to actions and events such as changes of database state. Some popular active database research prototypes include HiPAC [5] ODE [7] Postgres [26] Starburst [9] These systems support powerful rules and allow very general events, conditions, and actions, and ....

....very general events, conditions, and actions, and therefore are difficult to implement efficiently. The result is fairly restricted implementations (e.g. built in triggers [11] in relational database management systems such as Oracle, Sybase, and Informix) Active queries, introduced in Alert [24], are more sophisticated than database triggers, since they can be defined on multiple tables, on views, and can be nested within other active queries. However, active queries rely heavily on a number of extensions specific to the IBM Starburst DBMS [9] Comparing with the state of art of ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

....to scale up to the distributed interoperable environment. Active Databases: Event Condition Action (ECA) systems are rule based programs in which an event triggers the testing of a condition, which in turn (if true) triggers an action. Most of active database systems [15] provide facilities [2, 12, 13, 5, 14, 4] that support ECA rules referring to actions and events such as changes of database state. Some popular active database research prototypes include Ariel [5] Postgres [14] and Starburst [4] These systems support powerful rules and allow very general events, conditions, and actions, and ....

....events, conditions, and actions, and therefore are difficult to implement efficiently. The result is widely adopted in a restricted form of implementations (e.g. built in triggers in relational database management systems such as Oracle, Sybase, and Informix) Active queries, introduced in Alert [13], are more sophisticated than database triggers, since they can be defined on multiple tables, on views, and can be nested within other active queries. However, active queries rely heavily on a number of extensions specific to the IBM Starburst DBMS [4] Comparing with the state of art of ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

....these assumptions no longer hold (see [21] for a summary of desired system properties in the Internet) and some of the techniques do not easily extend to scale up to the distributed interoperable environment. 7.2. 1 Active Databases Most of active database systems [38] provide facilities [6, 30, 35] that allow users to specify, in the form of rules, actions to be performed following changes of database state. Despite their conceptual generality, rules have been so far supported in a fairly restrictive form in practical systems, for example, by built in triggers [15] in relational database ....

.... have been so far supported in a fairly restrictive form in practical systems, for example, by built in triggers [15] in relational database management systems such as Oracle, Sybase, and Informix (see a further discussion On Commercial database trigger below) Active queries, introduced in Alert [35], is yet another form of ECA rules. Active queries are more sophisticated than database triggers, since they can be defined on multiple tables, on views, and can be nested within other active queries. However, active queries heavily rely on the use of active tables as system built in capability ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

....two tokens jointly, or the union of the two different states reached by the two tokens (provided they never meet) Then, the accept relation due to the second computation is equal to R 1 [ R 2 . 2 The proof for all three theorems is given in the Appendix. 9 Related Work In the Alert system [SPAM91] basic events are inserts deletes updates to tables that have been declared active. Composite events are SQL queries defined over active tables. The attributes of the events are the values of the tuple inserted deleted updated, There is no notion of time, and unless time is coded as one of the ....

Ulf Schreier, Hamid Pirahesh, Rakesh Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proceedings of the Seventeenth International Conference on Very Large Databases (VLDB), pages 469--478, Barcelona, Spain, September 3-6 1991.

....controlled in a database. When applied to an open information universe as the Internet, these assumptions no longer hold, and some of the techniques do not easily extend to scale up to the distributed interoperable environment. Comparing with the state of art of research in active databases [12, 9, 10, 4, 11, 3], the JCQ system differs primarily in the following three ways: First, the JCQ system targets at update monitoring on the Web, handling both structured database sources and semistructured sources such as HTML files. Second, the continual query concept can be seen as a practical and useful ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proceedings of the International Conference on Very Large Data Bases, pages 469--478, Barcelona, Spain, September 1991.

....only those specified by OAG but also those defined by application systems are supported. The concept and use of ECAA rules for constraint specification and enforcement is adapted from some existing active database management systems [ACT96, HAN93] such as HiPAC [DAY88, BUC95] Ariel [HAN92] Alert [SCH91], Sentinel [CHA94a] POSTGRESS [STO91] ODE [GEH91, GEH96] Starburst [LOH91, WID90] and our own work on OSAM .KBMS [SU91, SU92, SU93, SU95, SU96a, SU96b, SHY96] In active systems, database operations or user defined operations can be treated as events, which can trigger the execution of rules. ....

Schreier, U., Pirahesh, H., Agrawal, R., and Mohan, C., "Alert: An architecture for transforming a passive DBMS into an active DBMS," Proceedings of the 17 th International Conference on Very Large Data Bases, Barcelona (Catalonia, Spain), September 1991, pp. 469-478.

.... not provide a data structure for testing selection conditions, or ffl provide a data structure for testing selection conditions which cannot efficiently handle conditions placed on an arbitrary attribute (e.g. one without an index) POSTGRES rule system [19, 20, 21] HiPAC [3] DIPS [17] Alert [16]) Other distinguishing features of Ariel are its close adherence to the production system model, its unified treatment of rules with normal conditions as well as event based and transition conditions, its ability to run rule action commands without creating any additional joins to the P node, and ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive DBMS into an active DBMS. In Proc. 17th International Conference on Very Large Data Bases, Barcelona, September 1991.

....rule system is a production rule system tightly integrated into the transaction management. Among others starburst research addresses problems of rule interference, termination and scheduling of rule sets. The Starburst rule system is implemented. Another Starburst rule extension is Alert [SPAM91] References: ACL91] AWH92] Cha93] CW91] CW90] CW92] LLPS91] Wid92a] Wid92b] Wid93] WCL91] WF89] WF90] Secondary: HJ91] HW93] PDW 93] SPAM91] 3 Special Issues In the following we group the publications according to various issues in the context of active ....

....and scheduling of rule sets. The Starburst rule system is implemented. Another Starburst rule extension is Alert [SPAM91] References: ACL91] AWH92] Cha93] CW91] CW90] CW92] LLPS91] Wid92a] Wid92b] Wid93] WCL91] WF89] WF90] Secondary: HJ91] HW93] PDW 93] SPAM91] 3 Special Issues In the following we group the publications according to various issues in the context of active database systems. 3.1 Initial Reading Recommended for initial reading in the field of active database systems or special topics are: References: Cha93] Day88] DG93] HW93] ....

[Article contains additional citation context not shown here]

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proc. 17th Int'l. Conf. on Very Large Data Bases, Barcelona, September 1991.

....object oriented data models using the services of relational DBMS s [32, 15] Here, the layer is used to make a paradigm shift from a relational to an object oriented model, and upward compatibility is not considered. In other research, a passive DBMS (Starburst) was converted to an active DBMS [20]. A small extension to SQL was implemented using a layered architecture, with the goal of maximum reuse of the underlying, passive DBMS. The rest of the paper is organized as follows. In Section 2 we first characterize temporal support and motivate the need for a temporal SQL. Then the layered ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. Proceedings of the VLDB Conference, pages 469--478, 1991.

.... et al. 1989] Dayal et al. 1988] McCarthy and Dayal 1989] Gehani and Jagadish 1991] Stonebraker et al. 1990] Stonebraker and Kemnitz 1991] Delcambre and Etheredge 1988] Widom et al. 1991] Widom and Finkelstein 1990] Beeri and Milo 1991] Cohen 1989] Diaz et al. 1991] Kotz et al. 1988] [Schreier et al. 1991] [Simon et al. 1992] Buchmann 1990] E. Anwar 1993] S. Gatziu 1991] In this chapter, we will illustrate the features of active database systems using Ariel [Hanson 1992] HiPAC [Chakravarthy et al. 1989, Dayal et al. 1988, McCarthy and Dayal 1989] POSTGRES [Stonebraker et al. 1990, ....

....3.5 HiPAC Before describing run time rule processing in HiPAC, it is necessary to introduce the concept of coupling modes. Coupling modes originated in the HiPAC project but subsequently have been discussed in the context of other active database systems, e.g. Gehani and Jagadish 1991, Schreier et al. 1991, S. Gatziu 1991, E. Anwar 1993, Buchmann 1990] Coupling modes determine how rule events, conditions, and actions relate to database transactions. Whereas in Ariel, POSTGRES, Starburst, and many other active database systems, rule conditions are evaluated and actions are executed in the same ....

Schreier, U., Pirahesh, H., Agrawal, R., and Mohan, C. (1991). Alert: An architecture for transforming a passive DBMS into an active DBMS. In Proceedings of the Seventeenth International Conference on Very Large Data Bases.

....of relationship can not be expressed by most event specification languages in literature. Finally, we develop a detection algorithm that uses a tree structure to efficiently monitor composite events. 1 1 Introduction Recently rule system have been applied in various database research efforts [CW91, SPAM91, SK91, Cho92, GJS92, GD93, SW95]. A problem in study of rule systems is the specification of the events. Since the early study of this problem by [DBB 88] many proposals have been seen in literature. Research efforts studying event specification are forced in the design of specification languages, event semantics, expressive ....

SCHREIER, U., PIRAHESH, H., AGRAWAL, R., AND MOHAN, C., Alert: an architecture for transforming a passive DBMS into an active DBMS, VLDB'91, pp.469-478.

.... [Mor84] where some of the characteristics of active databases are discussed, and a semantic constraint language is proposed) CW91, WF90] where SQL is extended to incorporate constraint specification, and constraints generate production rules that check updates over tuples or sets of tuples) SPAM91] where it is shown how to extend a relational system with a layer that manages special active relations, which control events and allow trigger execution) SZ91] where the problem of optimizing the execution of large sets of rules by materializing specific relations is considered) ....

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings 17th VLDB, pages 469--478, 1991.

....of multiple events. Because declarative constraints are supported using rules, these systems cannot benefit from the important semantic query optimization techniques [23] In contrast to the OPS5 models, triggers appearing in the marketplace are more procedural, a la Postgres [33] Alert [31] and Update Dependencies [4, 25] Once activated, a trigger will be eventually executed, and if a trigger action causes an event that activates another trigger, the newly activated triggers are executed immediately. The burden for controlling triggering based on the net effect of database ....

Ulf Schreier, Hamid Pirahesh, Rakesh Agrawal, and C. Mohan. Alert: An architecture for transforming a passive DBMS into an active DBMS. In Proc. of the 17th Int. Conf. on Very Large Data Bases, pages 469-- 477, Barcelona (Catalonia, Spain), September 1991.

No context found.

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proceedings of the 17th International Conference on Very Large Data Bases (VLDB), pages 469--478, September 1991.

No context found.

Schreier U, Pirahesh H, Agrawal R, Mohan C (1991) Alert: an architecture for transforming a passive DBMS into an active DBMS. In: Proceedings of the 17th international conference on very large data bases, Barcelona

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Schreier, U., Pirahesh, H., Agrawal, R., and Mohan, C., "Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS," in Proceedings of the International Conference on Very Large Data Bases, (Barcelona, Spain), pp. 469--478, September 1991.

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Schreier U, et all., "Alert: An architecture for transforming a passive dbms into an active dbms, ACM-SIGMOD International Conference on Management of Data, September 1991, pp. 469-478.

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U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS. In Proc. of the 17th VLDB Conference, pp. 469--478, Barcelona, 1991.

No context found.

U. Schreier, H. Pirahesh, R. Agrawal and C. Mohan, "Alert: An Architecture for Transforming a Passive DBMS into an Active DBMS", Proc. of the 17th Int'l Conf. on Very Large Databases, Barcelona, Spain, Sept. 1991, 469-478.

No context found.

U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. In Proceedings of the Seventeenth International Conference on Very Large Databases, pp. 469--478, Barcelona, Spain, September 1991.

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