Douglas N. Gordin and Alexander J. Pasik. Set-oriented constructs: From rete rule bases to database systems. In Proceedings 10th ACM Symposium on PODS, pages 60--67, 1991.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....the overhead of the locking mechanism significantly. 2.4. 3 Set Functions Recent work on incorporating rule based systems into database systems has indicated that increased efficiency and ease of programming can be obtained through the use of set based rules rather than instance based rules [ Gordin and Pasik, 1991, Widom and Finkelstein, 1990, Sellis et al. 1987 ] In the instance based implementation of a rule based system, one and only one rule instantiation is created for each set of working memory elements which match a lefthand side. That is, if the lefthand side of a rule has N positive condition ....

Douglas N. Gordin and Alexander J. Pasik. Set-oriented constructs: From rete rule bases to database systems. In Proceedings 10th ACM Symposium on PODS, pages 60--67, 1991.

.... DeltaC (recall Definition 5) is nonempty. That is, the condition is true whenever the query produces new tuples. This is identical to the interpretation of conditions in the CA rules of, e.g. Ariel [Hanson 1992] RPL [Delcambre and Etheredge 1989] and set oriented adaptations of OPS5 [Gordin and Pasik 1991]. We observe that this interpretation of CA rule conditions represents the most important difference with how rule conditions are evaluated in the ECA rule model described in the previous section. The action A is a data modification operation executed on the current database state, identical to ....

....conditions represents the most important difference with how rule conditions are evaluated in the ECA rule model described in the previous section. The action A is a data modification operation executed on the current database state, identical to ECA rules. In some active database systems, e.g. [Gordin and Pasik 1991; Hanson 1992] a rule s action implicitly operates only on the data selected by the condition, rather than on the entire database. We could use a similar rule model here, but it would complicate the syntax and semantics and has no bearing on our analysis methods; see Section 9 for further ....

[Article contains additional citation context not shown here]

Gordin, D. and Pasik, A. 1991. Set-oriented constructs: From Rete rule bases to database systems. In Proceedings of the ACM SIGMOD International Conference on Management of Data (Denver, Colorado, May 1991), pp. 60--67.

....bases. One research effort in DBMS rule processing has been to extend the syntax of production rule languages with set oriented constructs and use more efficient set oriented DBMS query processing strategies to evaluate conditions and execute actions of rules. This research has been reported in [8, 9, 10, 15, 36, 37, 44]. Parallelism has also been used to improve the efficiency in executing rule actions as well as in evaluating conditions [2, 6, 16, 17, 18, 20, 24, 27, 34, 35, 39] Research reported in [2, 6, 18, 34, 35, 39] has investigated the execution of a number of rules in parallel, and the corresponding ....

....by events which could be updates to the database as well as external events. Their research has produced some interesting results on the transaction boundaries within which C A pairs execute. Finally, research in language constructs to specify and support set oriented rules, by Gordin and Pasik [15], and Widom and Finkelstein [44] has also impacted our research on concurrent execution within a transaction and is discussed in a later section. 4. AN ARCHITECTURE FOR CONCURRENTLY EXECUTING RULES The architecture for a relational DBMS implementation of a rule sub system is illustrated in ....

[Article contains additional citation context not shown here]

Gordin, D.N. and Pasik, A.J. Set-oriented constructs: from Rete rule bases to database systems. Proceedings of the ACM-SIGMOD International Conference on the Management of Data (1991).

....are either not developed in detail or limited to procedural matching done on the righthand side only. It was not until recent years, when the interest on expert database systems growing rapidly, that the set oriented or similar extensions to production systems became a focus of attention (e.g. [1, 17, 3]) However, the design goal of most of the database production languages or systems is to integrate databases and expert system shells. Performance and parallel processing are considered as secondary or even not considered at all. Here instead, we consider set oriented constructs as a formalism ....

....databases and expert system shells. Performance and parallel processing are considered as secondary or even not considered at all. Here instead, we consider set oriented constructs as a formalism for expressing semantic knowledge for increasing concurrency. We discuss Gordin and Pasik s work [3]. Gordin and Pasik have developed several setoriented constructs and showed how these constructs can be added to a DBMS implementation of OPS5. The new constructs are implemented by an extended version of the Rete algorithm [2] A condition element (CE) is set oriented if it is enclosed in square ....

Douglas N. Gordin and Alexander J. Pasik. Setoriented constructs: From Rete rule bases to database systems. In ACM SIGMOD Intl. Conf. on Management of Data, pages 60--67, 1991.

....language such as OPS5 [BFKM85] to a conventional DBMS; this approach is taken in, e.g. Tzv88] More recently the prevalent approach has been to build rule processing directly into the database system. Examples of recent or ongoing projects in expert database systems are [BM93,DE89,DOS 92,GP91,SLR88] Note that some systems described as active database systems This work was partially performed while the authors were at the IBM Almaden Research Center, San Jose, CA. At Stanford this work was supported by equipment grants from Digital Equipment Corporation and IBM Corporation. y ....

....and set oriented adaptations 1 For simplicity, we consider rules with a single action here, although many expert database systems allow rules with a sequence of actions. Our methods easily extend to multiple actions, usually simply by applying the method once for each action [Bar94] of OPS5 [GP91] it also is similar to the way many Event Condition Action rules appear to be programmed in practice [CW90] The action E act is a normal data modification operation executed on the current database state. In some expert database systems, e.g. GP91,Han92] a rule s action implicitly operates ....

[Article contains additional citation context not shown here]

D.N. Gordin and A.J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In Proceedings of the ACM SIGMOD International Conference on Management of Data, pages 60--67, Denver, Colorado, May 1991.

.... speed increases in the matching phase of production systems by means of storing collections of WMEs instead of single WMEs in the Rete Network [2] Gordin and Pasik explored the use of set oriented constructs as a means to integrate database management systems (DBMS) and rule based systems [26]. Wu and Browne proposed the use of setoriented constructions in an object based model for parallel rule based systems, their goal is to increase concurrency [91] An expansion on the use of collections to construct a parallel firing, asynchronous, collection oriented system is still to be further ....

D. N. Gordin and A. J. Pasik, Set-oriented constructs: From rete rule bases to database systems, in Proceedings of the 1991 ACM SIGMOD International Conference on Management of Data, May 1991, pp. 60--67.

.... relevant rules and for the specification of causal dependencies between different groups of rules) By providing this set of minimal but semantically rich constructs and their formal semantics, we greatly clarify and formalize the essential elements of the so called set oriented constructs [34, 52, 142, 156] in production systems. ffl A semantic based interference analysis technique for rule systems based on data relationship specifications. This technique determines parallel executable rules based on user supplied semantic information in the form of functional dependency. Our notion of functional ....

....On the contrary, our approach is intended to be a much more general and comprehensive one that exploits semantic parallelism at every level of production system. The application specific knowledge is also expressed and used in a much more natural way. 2.2. 8 Gordin and Pasik s Work In [51, 52], Gordin and Pasik have developed several set oriented constructs and showed how these constructs can be added to a DBMS implementation of OPS5. The new constructs are implemented by an extended version of the Rete algorithm [44] A condition element (CE) is set oriented if it is enclosed in ....

[Article contains additional citation context not shown here]

Douglas N. Gordin and Alexander J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In ACM SIGMOD Intl. Conf. on Management of Data, pages 60--67, 1991.

....made in the indicated space ffl Lock space: Forbid any changes to be made to the memory space. ffl Current space: Return the identifier of the current space. In addition to the above commands, our production system includes a set oriented semantics similar to that described by Gordin and Pasik [6] the use of this construct allows the programmer to match selected sets of working memory elements on the lefthand side of the rule and copy them into a new state. The addition of many new righthand side operators to the language represents a tradeoff in programming versus representational ....

Douglas N. Gordin and Alexander J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In Proceedings 10th ACM Symposium on PODS, pages 60--67, 1991.

....processor for a production rule language such as OPS5 [7] to a conventional DBMS; this approach is taken in, e.g. 23] More recently the prevalent approach has been to build rule processing directly into the database system. Examples of recent or ongoing projects in expert database systems are [6, 11, 12, 13, 21]. Note that some systems described as active database systems actually use the Condition Action rule paradigm, and hence fall into the class of expert database systems as we use the term here; examples of such systems are [14, 22] Since expert database systems evolved from production rule systems ....

....has not previously been evaluated, then E old cond = That is, informally, the condition is true whenever the query produces new tuples. This is identical to the interpretation of conditions in the Condition Action rules of, e.g. Ariel [14] RPL [11] and set oriented adaptations of OPS5 [13]; it also is similar to the way many Event Condition Action rules appear to be programmed in practice [10] The action E act is a normal data modification operation executed on the current database state. In some expert database systems, e.g. 13,14] a rule s action implicitly operates only on ....

[Article contains additional citation context not shown here]

D.N. Gordin and A.J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In Proc. ACM SIGMOD Int'l Conf. on Management of Data, pages 60-- 67, May 1991.

....If the rule has not previously been evaluated, then C old = That is, informally, the condition is true whenever the query produces new tuples. This is identical to the interpretation of conditions in the CA rules of, e.g. Ariel [Han92] RPL [DE89] and set oriented adaptations of OPS5 [GP91] The action A is a normal data modification operation executed on the current database state. In some active database systems, e.g. GP91,Han92] a rule s action implicitly operates only on the data selected by the condition, rather than on the entire database. We could use a similar rule model ....

.... new tuples. This is identical to the interpretation of conditions in the CA rules of, e.g. Ariel [Han92] RPL [DE89] and set oriented adaptations of OPS5 [GP91] The action A is a normal data modification operation executed on the current database state. In some active database systems, e.g. GP91,Han92] a rule s action implicitly operates only on the data selected by the condition, rather than on the entire database. We could use a similar rule model here, but it would complicate the syntax and semantics and has no bearing on our analysis methods; see Section 7 for further discussion. ....

[Article contains additional citation context not shown here]

D.N. Gordin and A.J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In Proceedings of the ACM SIGMOD International Conference on Management of Data, pages 60--67, Denver, Colorado, May 1991.

.... and firing rules to saturation are explored in RDL1, a production rule implementation of a deductive database system [12, 30] A related modification to the recognize act cycle is setoriented firing, in which the selected rule s action is executed once for the entire set of instantiations [21]. Ariel and Starburst both use a form of set oriented firing; see Sections 4.1 and 4.5. In active database systems, where production rule processing is fully integrated with conventional database activity (e.g. queries, modifications, transactions) a pure recognize act semantics is not always ....

D. N. Gordin and A. J. Pasik. Set-oriented constructs: From Rete rule bases to database systems. In Proceedings of the ACM SIGMOD International Conference on Management of Data, May 1991.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC