Widom, J.: The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering. (1996) Vol. 8, Issue: 4, 583-595  Home/Search   Document Details and Download   Summary   Related Articles   Check

....a natural language template interface for specifying rules. 2.7 Rules in Academic Research Prototypes There are a number of research prototypes implementing certain forms of rules, mainly in a database context. Examples of ECA rule ( active database ) systems are Ariel [Han96] Starburst [Wid96], and HiPAC [MD89] An example of a derivation rule ( deductive database ) system is ConceptBase [Con] 2.8 Open Source Rule Systems There is one open source rule system that deserves a special mention: Mandarax [Man] a java class library for derivation rules that supports the export and import ....

J. Widom. The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, 1996. 21

....is absent in real time databases. In this chapter, we survey active databases, real time databases, and the cooperative transaction models to provide a basis for our cooperative transaction model. 2. 1 Active Databases An active DBMS is a DBMS that supports Event Condition Action (ECA) rules [Dayal88, Chak92, WiCe96, Sell95, Widom96]. The semantics of ECA rules are as follows. When an event occurs, an action condition is evaluated; if the condition is satisfied, the rule is fired, and the action is scheduled for execution. An event may be a temporal event, the execution of a database 8 operation on an object, ....

Widom, J., "The Starburst Active Database Rule System", IEEE TKDE, Vol. 8, No. 4, August 1996.

....rule systems that investigate small amounts of data. Applications within this region are implemented using standard programming languages. Region II consists of simple rule systems that investigate large amounts of data. It is within this region that early active database research was focused [33, 97]. Region II applications require the sophisticated data retrieval methods of standard databases, but do not necessitate robust rule engines for complex searching. Representative applications include core system services such as view maintenance, integrity constraints, and workflow systems ....

....are implemented without a loss in performance. An obvious disadvantage of this approach is that the database internals must be known. Consequently, a substantial amount of knowledge and effort is required for development. The hybrid approach uses open database kits such as OpenOODB [96] Starburst [97], and Exodus [23] This approach retains many of the advantages of integrated approaches, including performance, while reducing the development effort by publishing an internal database API. A disadvantage of the hybrid approach is that this published API tends to be quite complex. Further, ....

[Article contains additional citation context not shown here]

J. Widom, "The Starburst active database rule system," IEEE Transactions on Knowledge and Data Engineering, August, 1996.

....database states and the edges are states that are linked as described above. An active database program s execution path is the path through an execution graph taken by a particular execution. 6. Due to the properties of MLMs, we do not have to consider rules that are un triggered as described in [27]. R S i 0 i n 1 V , E , R S 9 ( R U ( 9 R ( Triggers A ( U R U Apply Y 9 , 9 Triggers Y ( U 3.3. Monotonic Log Monitor Definitions Consider an active database ....

....presented in [2,18] We present three slightly different models that vary depending on their restrictiveness with respect to concurrency. In all three models, rule execution begins with the occurrence of an external event. The first model, the Sequential model, is based on algorithms presented in [2,3,27]. The model execution proceeds by locking the database from external events and serially executing until quiescence. Though straightforward, the Sequential model forfeits concurrency. Therefore, we introduce the the Parallel and the ActiveDatabase execution models. The Parallel model allows for ....

[Article contains additional citation context not shown here]

J. Widom, "The Starburst Active Database Rule System," IEEE Transactions on Knowledge and Data Engineering, August, 1996.

....[15] Typically, the model adopted is quite a low level one, and consists in system observers merely accepting events from the reactive elements of the system. In the database area, a number of research prototypes of active DBMS have been developed, such as Ariel [11] Sentinel [4] Starburst [29], Postgress [24] Chimera [5] etc. Most of them support composite events, allowing internal ECA rules to be activated when two or more events occur. Our Synchronizer component of the Observation Interface abstraction performs a work that could be analogous to the composite event detection [6] ....

L. Widom, The Starburst Active Database Rule System. IEEE Transactions on Knowledge and Data Science, 8(4): 583--595, 1996.

.... to a given port events of insertion, deletion and update of tuples (see for example Oracle Triggers [25] Some research prototypes of active DBMS have been developed on the basis of Event Condition Action model (ECA) and active rules model [1, 12, 10] Some examples are HiPAC [9] Starburst [29] and Chimera [6] Most of them support composite events [7] allowing internal ECA rules to be activated when two or more events occur. Our Synchroniser component performs a task that could be analogous to a composite event detection, but which is implemented outside the DBMS. This allows existing ....

Widom, J. (1996). The Starburst Active Database Rule System. IEEE Transactions on Knowledge and Data Science, 8(4): 583--595.

....in HiPAC, namely, recent, chronicle, continuous and cumulative contexts. Sentinel currently supports immediate and deferred modes of rule execution [CHA93, CHA94b, CHA94a] 2. 2 Starburst The Starburst system is a prototype extensible relational DBMS developed at the IBM Almaden Research Center [WID96a]. Startburst s extensibility allows the database 7 system to be customized for advanced and non traditional database applications. One of Starburst s extensions is an integrated active database rule processing facility called the Starburst Rule System. The Starburst rule language differs from ....

Widom J. (1996), The Starburst Active Database Rule System, IEEE Transactions on Knowlede and Data Engineering, Vol. 8, No. 4, pp. 583595

....been achieved, but others have only been foreshadowed. Active rules are speci cations of stereotypical reactions automatically performed by a DBMS in response to the detection of particular DB related events. A lot of attention has been devoted from research community to active databases so far [13, 15, 16, 18, 26]. A wide range of potential applications of the active rule concept have been identi ed; they can be distinguished in two major classes: external applications and internal applications. External applications concern reactions to external real world stimuli that have some e ects on the enviroment ....

J. Widom. The Starburst Active Database Rule System. In IEEE Transactions on Knowledge and Data Engineering, 8(4):583-595, August 1996.

.... union, join, di erence and renaming) against c tables (or against tables of the more general type) can be evaluated in polynomial time [8] 4 Active Database Rule Language The syntax for de ning an E C A rule is as follows, which is similar to the rule language used in the Starburst system [17]: create rule name when transition predicate if condition then action Transition predicates are statements about the changes of the database. Conditions are statements about the current state of the database. Actions are data manipulation operations. Like in the Startburst system, a ....

J. Widom. The starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):582-595, August 1996.

....FACTORS AFFECTING THE SCHEDULING OF TRIGGERED TRANSACTIONS 2.1 Scheduling of Triggering Transactions Coupling mode defines the creation time of a triggered transaction and its relationship with the triggering transaction as required by different applications. In the deferred coupling mode [4] [5], the triggered transaction is generated after the completion of the triggering transaction. In the immediate coupling mode [4] 5] the triggered transaction is generated immediately once the condition for triggering is satisfied. The execution of the triggering transaction will be suspended ....

....creation time of a triggered transaction and its relationship with the triggering transaction as required by different applications. In the deferred coupling mode [4] 5] the triggered transaction is generated after the completion of the triggering transaction. In the immediate coupling mode [4] [5], the triggered transaction is generated immediately once the condition for triggering is satisfied. The execution of the triggering transaction will be suspended until the completion of the triggered transaction. The triggered transaction may be defined as a sub transaction of the triggering ....

J. Widom, "The Starburst Active Database Rule System", IEEE Transactions on Knowledge and Data Engineering, volume 8, number 4, pp. 583-595, 1996.

....when certain events speci ed in the rule occur, and provided that their (optional) conditions hold; when a rule so triggered is executed, the actions speci ed in the Draft February 15, 2000 3 rule are carried out. For concreteness we use the syntax and semantics of the Starburst rule system [24]: a rule is assumed to have the structure rule RuleName on Relation when EventList if C then Action where EventList speci es a set of events that cause the rule to be triggered. The execution of a triggered rule involves the evaluation of the condition C, and if this evaluates to true, ....

J. Widom, \The Starburst Active Database Rule System", IEEE Transactions on Knowledge and Data Engineering, 8(4):583-595, August 1996.

....providing a unifying criteria regarding the meaning of active rules, and to provide a framework for comparing different proposals for active database systems. This chapter is structured as follows. Section 1. 2 describes the execution modes of active rules, in particular of rules in Starburst [17]. Section 1.3 introduces Sitcalc and specifications of database updates. It continues with a more precise description of the task of specifying transactions and active rules. The section ends with the introduction of occurrences in Sitcalc [13] Section 1.4 shows how to represent and specify ....

....with higher flexibility in the relationship between rules and transactions. We use Starburst as a model in order to describe our approach to specify the semantics of active rules. In the next section we describe how Starburst addresses these issues. 1.2. 1 Starburst Active rules in Starburst [17] are associated to the notion of a transition. The action in a rule may be a sequence of SQL operations. When this sequence is executed, it gives rise to a transition. A transaction may involve several transitions; the first transition results from the execution of the operations explicitly ....

[Article contains additional citation context not shown here]

J. Widom. The Starburst Active Database Rule System. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, 1996.

....formal logic based model for this transaction oriented semantics, show that it is amenable to efficient implementation, and prove that it solves the non termination problem. 1 Introduction Several active database languages and systems have been developed so far a very incomplete list include [3, 6, 9]. Furthermore, active rules are now becoming a part of several commercial databases and of the SQL3 proposed standards. Indeed, active databases represent a powerful new technology that finds important applications in the market place. However, this new technology is faced with several technical ....

....enforcing integrity constraints via active rules, and this framework will be adopted in this paper as well. Furthermore, while in the immediate interpretation of coupled semantics, rules are fired as soon as Event is detected, the deferred semantics used in Starburst is more transaction conscious [9], inasmuch as it recognizes the fact that only net changes resulting from a complete transaction are of significance, while transient changes caused by individual events during the transaction are not. For instance, the insertion of a record r, followed by the deletion of the same r within the ....

[Article contains additional citation context not shown here]

Widom J., "The Starburst Active Database Rule System", To appear in IEEE Trans. On Knowledge and Data Engineering.

....database system is likely to reduce size and complexity of the resulting overall system. Other methods that propose the usage of triggers for propagating updates are presented by Ceri and Widom in [CW90, CW91, CW94] These approaches are related to the relational Starburst production rule system [Wid96]. A main difference between the method in [CW94] and our approach is that Ceri and Widom assume the database to be entirely materialized, ie all derived relations are explicitly stored. The authors propose a transformation technique compiling stratifiable deductive rules into triggers. These ....

Jennifer Widom. The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, August 1996. ESPRIT Project 6333

.... technology was originally proposed to strengthen the power of integrity enforcement by database management systems (Eswaran and Chamberlain 1975) Since then the concept was generalized to handle more general rules in HiPAC (McCarthy and Dayal 1989) POSTGRES (Stonebraker et al. 1990) Starburst (Widom 1996), and ODE (Agrawal and Gehani 1989) Among these, the HiPAC project proposed Event Condition Action (ECA) rules, as a general formalism of active database management functions. An ECA rule, as the name suggests, comprises three parts. The first part specifies the relevant events, such as update of ....

Widom, J. (1996). The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering 8(4), 593--595.

....capabilities of active databases are useful for many applications, such as views [9, 10] integrity constraints [36, 8] and workflows. Several active database languages [33, 22, 21] have been proposed, and many systems and prototypes have been designed and, partially or completely, implemented [25, 28, 11, 19, 34, 39] (many systems are presented in the collection [40] Each system has some active features, expressed in its own syntax and (operational) semantics. However, it can be noticed that sometimes rules with a similar form will behave differently in different systems ( 24, 13] present surveys of ....

.... The triggering event is specified as: e dept del(D#) after del(dept(D#; Dname;Div; Loc) and the active rule is: r dept emp(D#) e dept del(D#) consumed (local) initiates del(emp(E#; Ename; JobT itle; Sal; D#) Last example illustrates that we could easily encode the example given in [39] (Section 5) however, we d like to make a subtle observation. The aforementioned example uses the aggregate statement avg from SQL. We can demonstrate that the calculation of an average value can be accomplished by using active rules, with undesirable inefficiency. We leave for future work how to ....

J. Widom. The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, 1996.

....The action part of a rule may be executed in one transaction immediately as a linear extension of the triggering transaction. This is called coupled execution [HLM88] In coupled execution, we do not have intra rule concurrency. We can give Starburst as an example of coupled execution of rules [Wid96] AWH92] In Starburst, rules are based on the notion of transitions. A transition is a change in database state resulting from the execution of a sequence of data manipulation operations. Rules are activated at assertion points. There is an assertion point at the end of each transaction and ....

Jennifer Widom. The starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, August 1996.

....rules defining attributes and constraints, an implementation section also contains the code of each targeted operation as well as the active rules implementing targeted triggers. The active rule language of Chimera is based on a set oriented semantics similar to that of the Starburst rule system [19]. The event part of an active rule consists of one or more event pattern specifying situations in which the rule is to be activated. At present, only occurrences of data manipulation requests concerning the class under consideration are viewed as events. Event patterns may not be parameterized as ....

J. Widom. The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, 1996.

....capabilities of active databases are useful for many applications, such as views [9, 10] integrity constraints [36, 8] and workflows. Several active database languages [33, 22, 21] have been proposed, and many systems and prototypes have been designed and, partially or completely, implemented [25, 28, 11, 19, 34, 39] (many systems are presented in the collection [40] Each system has some active features, expressed in its own syntax and (operational) semantics. However, it can be noticed that sometimes rules with a similar form will behave differently in different systems. In [24, 13] it can be found a ....

....action in the previous state. Example 2 The reaction to an event (i.e. determining if an active rule is triggered due to a particular event) has different policies in different systems. For example, in Postgres [34] active rules are triggered by the occurrence of an event. Meanwhile, Starburst [39] in which the rule processing is set oriented (as opposed to tuple oriented rule processing in Postgress) the set of triggered rules is determined at the end of user transaction, based on the net effect of the events 1 . The premises for defining a net effect in Starburst are: ffl If a tuple ....

[Article contains additional citation context not shown here]

J. Widom. The starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering, 8(4):583--595, 1996.

No context found.

Widom, J.: The Starburst active database rule system. IEEE Transactions on Knowledge and Data Engineering. (1996) Vol. 8, Issue: 4, 583-595

No context found.

Widom J., "The Starburst Active Database Rule System", To appear in IEEE Trans. On Knowledge and Data Engineering.

No context found.

Widom J., "The Starburst Active Database Rule System", To appear in IEEE Trans. On Knowledge and Data Engineering.

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