M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in data base systems. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 281--290, 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....cultural and historical biases might also have had a role in this chasm, the root of the problem is actually technical and can be traced to certain semantic inadequacies in both approaches. Several active database languages and systems have been proposed so far: a very incomplete list include [3, 5, 9, 19, 20, 29]. However, there is is no unifying semantic theory for active databases: most of the work done so far has concentrated on explaining operational semantics of particular systems. On the contrary, deductive databases are endowed with extraordinarily rich semantic foundations: not one but three ....

....condition action rules tend to be complex and expensive to support. For these reasons, more recent systems favor an alternative approach where the events that can trigger the firing of the rules are stated explicitly in the bodies of the rules. 6 Event Action Rules In systems such as Postgres [29], the events upon which a rule fires are stated explicitly. These rules can be easily modeled in our framework. For instance, the previous active rules involving students and courses could be expressed as follows: Example 10 Event driven rules add(grad(S, cs10, grad(S, cs20, grad(S, ....

M.L. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedure, caching and views in data base systems. In ACM SIGMOD International Conf. on Management of Data, pages 281--290, 1990.

....of Datalog including deletions are investigated, and the language RDL1 [dMS88] provides a seperate component for explicit control of the bottom up evaluation. Moreover, updates in production systems (e.g. OPS5 [BFKM86] and corresponding extensions of relational databases by rules (e.g. SJGP90, WF92, ZH90] are realized by applying the rules in a bottom up way, and, finally, also some database programming languages which incorporate rules follow this way (e.g. PDR91, HJ91] From those deductive languages involving objectoriented features, only a few provide update concepts, e.g. ....

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in data base systems. In Proc. of the ACM SIGMOD Symp. on the Management of Data, pages 281--290, 1990.

....the stock is too high) This need has led to the design of active databases, in which events of various kinds (e.g. a query, an update) may cause the firing of so called active rules. Many proposals for using active rules in databases have appeared, both commercial [3,4,19,26,36] and academic [11,14,18,21,25,30,33,37,38,40,41,42] (the latter usually being more flexible than the former) In order to assign a clear semantics to active rules, several approaches have been proposed to integrate active rules in a deductive framework. In assigning a semantics to these activedeductive languages, two main approaches emerged. The ....

.... both of the conflicting updates should be discarded, e#ectively leaving EDB in the same state as before with regard to a (in our framework, this can be obtained by returning insert if a was already in EDB, delete otherwise) The rule priority policy, found in systems such as Ariel [25] Postgres [37] and Starburst [42] assumes that each rule has a (static or dynamic) priority associated with it; sel returns insert or delete as needed to execute the update requested by the highest priority rule (in our framework, this can be obtained by looking up priorities in P ) Other policies, like ....

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. In Proc. of the ACM SIGMOD Int. Conf. on Management of Data, pages 281--290, 1990.

....This would be too expensive. Instead, the system must consider dependencies between view definitions to minimize the cost of view refreshment. For instance, the system can keep information about the set of all root attributes used in the query defining the virtual class extension, in the style of [SJGP90] These and other optimization techniques, which are related to materialized virtual data maintenance, are currently being studied and should be implemented in the near future. The update of virtual attributes to which an on update clause has not been defined or for which the system cannot ....

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. In Proc. ACM SIGMOD Symp. on the Management of Data, pages 281--290, 1990.

....after each database update and for triggers to be executed at application command. The Hipac project, as described in [10, 11] introduced several trigger execution modes, which are the parameters of the integration mechanism. More work on this subject for relational systems is described in [7, 26] and for object oriented systems in [5, 12, 15, 20] Trigger behaviour The behaviour of isolated triggers is not as simple as presented above. On the contrary, several issues have to be dealt with. They can be categorised into two groups: single trigger semantics and multiple trigger semantics. ....

....by moving the left conflicting cell. This results in the original conflict and the repair could be repeated (forever) To prevent this behaviour and to guide the development of well behaving applications, a trigger design theory is needed. Although the relevance of a design theory is recognised [8, 11, 14, 20, 26], little research on this subject has been published. Work based on the relational model is described in [8, 24, 29] and work based on the object oriented model is described in [23] A pre requisite for the development of a trigger design theory is a formal description of trigger semantics. Some ....

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules procedures, caching and views in database systems. In Proceedings of the ACM SIGMOD conference, pages 281--290, 1990.

.... maintaining derived information, keeping users informed of activities or refreshing displays (for an overview of active databases, see [25] Research into active databases leading to the development of complete systems has generally fallen into one of two camps: Active relational databases [24, 26], which are based on the query language of the underlying database system, and thus support declarative expression of conditions and straightforward facilities for performing updates. Such systems generally have simple event specification languages and execution models. Active object oriented ....

.... maintaining derived information, keeping users informed of activities or refreshing displays (for an overview of active databases, see [25] Research into active databases leading to the development of complete systems has generally fallen into one of two camps: Active relational databases [24, 26], which are based on the query language of the underlying database system, and thus support declarative expression of conditions and straightforward facilities for performing updates. Such systems generally have simple event specification languages and execution models. Active object oriented ....

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in database systems. In Proc. ACM SIGMOD, pages 281--290, 1990.

....only look up the Price and Finance attribute from Dealer3 using the value of CarID for each tuple in the current answer set. This is likely to be much cheaper than computing a three way join from scratch. 2 1.2. Related Work Previous work on using views to answer queries includes [LY85, YL87, SJGP90, TSI94, CR94, CKPS95, LMSS95, RSU95] Subsequently, GHQ95, SDJY96] discuss how to answer aggregate queries using materialized aggregate views. TSI94, CKPS95] also describe how to incorporate their techniques in a traditional cost based query optimizer. The problem of view adaptation is related ....

M. Stonebraker, A. Jhingran, J. Goh and S. Potamianos. On rules, procedures, caching and views in database systems. In SIGMOD, 1990.

....point of view, they argued that a wide range of applications can benefit from procedural data. Then there is the current interest in so called active databases [21, 22] dealing with procedural data in the form of rules which can be stored together with the ordinary data in the database (e.g. [29]) Also in object oriented database systems [34] procedural data in the form of methods play a central role. Moreover, note that even current commercial relational database systems maintain various data dictionary relations containing meta information like relation names or view definitions. To ....

M. Stonebraker et al. On rules, procedures, caching and views in data base systems. In Garcia-Molina and Jagadish [9], pages 281--290.

....by the system when certain The work of this author has been partially supported by the ERCIM fellowship Information and Knowledge Systems. events occur (e.g. constraint maintenance [3] and for this reason, active databases have been extensively investigated and experimented in the last years [2, 6, 8, 10, 11, 12]. However, the various proposals generally suffer from a lack of formal semantics and it has been observed that as a consequence of this lack, very often active rule processing becomes quickly complex and unpredictable, even for relatively small rule sets [6] In addition, the implementation of ....

....active database systems. We start by introducing a simple transaction language based on a well known transaction model [1] and a quite general active rule language in the context of the relational model, whose computational model is set oriented (like [12] and differently from other approaches [11]) We will consider two different execution models for active rules: immediate and deferred [8] The former has no temporal decoupling between the event, condition and action parts. The latter has a temporal decoupling between the event part on one side and the condition and action parts on the ....

[Article contains additional citation context not shown here]

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in database systems. In ACM SIGMOD Int. Conf. on Management of Data, pp. 281--290, 1990.

....of new demanding applications, such as CAD, multimedia, robotics and expert systems. Along this line, several researchers have proposed the integration of production rule languages (traditionally used in expert system shells) within database environments [8] 11] 19] 22] 23] 25] [26], 30] while others have studied the possibility of adding deductive capabilities to database systems [1] 2] 4] 5] 20] 21] 28] As a result of these studies, advanced research prototypes have been produced (e.g. LDL , Coral, Starburst, Postgres) Moreover, recent releases of some ....

....that this semantics looses much of its effectiveness when dynamic operators (updates and actions in the case at hand) are introduced. As pointed out above, our approach is somehow reversed: we look at deductive rules as special cases of generalized active rules. In other approaches [6] 25] [26] it is shown how deductive rules can be implemented by means of active rules which are considered as a sort of low level notation. The work [25] illustrates how deductive rules can be implemented in Postgres [26] by means of active ones in which queries appear both in the event and in the action ....

[Article contains additional citation context not shown here]

M.L. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedure, caching and views in database systems. In ACM SIGMOD Int. Conf. on Management of Data, pages 281-- 290, 1990.

....(Year) John Wiley Sons, Inc. two independent research trends have emerged: on one hand the use of production rule languages (traditionally used in expert system shells) for expressing active computations, that is, manipulations of data to be executed automatically whenever certain events occur [5, 6, 7, 10, 13, 14, 15, 16, 17]; on the other hand the use of logic based rule languages for expressing, in a declarative way, complex database queries and deductive computations [1, 2, 3, 4, 11] From a practical point of view, the integration of these paradigms (active and deductive) into a unique homogeneous framework would ....

M.L. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedure, caching and views in database systems. In ACM SIGMOD Int. Conf. on Management of Data, pages 281--290, 1990.

....with DS to reason about the interaction of the constraints and the schema in terms of the object oriented paradigm which supports property inheritance and object referencing , along generalization and aggregation hierarchies, respectively. 1. 2 Related Work There has been considerable work [13, 14, 16] dealing with the expressive power of relational constraint management. They view database relations as the predicates of constraints. Chakravarthy [3] developed the notion of constraint compilation for each database relation. The constraints are compiled by the refutation of the negation for each ....

M. Stonebraker, A. Jhingran, J. Goh, and S Potamianos. On rules, procedures, caching and views in data base systems. In Hector Garcia-Molina and H.V. Jagadish, editors, Proc. ACM SIGMOD Intl. Conf. on Management of Data, pages 281--290, Atlantic City, 1990.

....to the user. In principle the rst problem vanishes, if veri cation techniques are used at design time [9] whereas the second one still remains. As an alternative a lot of attention has been paid to integrity enforcement. In most cases the envisioned solution is a Rule Triggering System (RTS) [1, 3, 4, 11, 15], where production rules are used to repair inconsistencies instead of rolling back. This is often coupled with design time or run time analysis of the rules [1, 3, 5, 13] In order to become a reasonable solution of the integrity enforcement problem an RTS has to satisfy several properties. In ....

M. Stonebraker, A. Juingran, J. Goh, S. Potaminos: On Rules, Procedures, Caching and Views in Database Systems , in Proc. SIDMOD 1990, pp. 281-290

....to the user. In principle the rst problem vanishes, if veri cation techniques are used at design time [44, 57, 58] whereas the second one still remains. As an alternative a lot of attention has been paid to integrity enforcement. In most cases the envisioned solution is an active database [18, 27, 59, 64, 65], where production rules are used to repair inconsistencies instead of rolling back. Although this is sometimes coupled with design time (or even run time) analysis of the rules [18, 27, 33, 63] the approach is not always successfull. Moreover, a satisfying theory for rule triggering systems with ....

M. Stonebraker, A. Juingran, J. Goh, S. Potaminos: On Rules, Procedures, Caching and Views in Database Systems , in Proc. SIDMOD 1990, pp. 281 - 290

....to the user. In principle the rst problem vanishes, if veri cation techniques are used at design time [9, 10, 16, 17] whereas the second one still remains. As an alternative a lot of attention has been paid to integrity enforcement. In most cases the envisioned solution is an active database [3, 5, 18, 21, 22], where production rules are used to repair inconsistencies instead of rolling back. Although this is sometimes coupled with design time (or even run time) analysis of the rules [3, 5, 7, 20] the approach as we will see is limited to non interfering constraints. Moreover, a satisfying theory ....

....into C 1 , hence the solution to the integrity enforcement problem with respect to T 1 = insert C1 (x) would simply be fail, whereas for T 2 = delete C 2 (x) the solution of Example 1 is still valid. ut 1. 2 The Active Database Approach and its Limitations In the active database approach [3, 5, 7, 18, 20, 21, 22] consistency is to be achieved by the use of production rules. A Rule Triggering System (RTS) is a nite partially ordered set of rules of the form ON heventi IF hconditioni THEN hactioni : Usually the event speci es the (primitive) database transformation that has been performed, the condition ....

M. Stonebraker, A. Juingran, J. Goh, S. Potaminos, On Rules, Procedures, Caching and Views in Database Systems, in Proc. SIDMOD 1990 , 281-290.

....Some extensions are also very limiting in terms of modeling or representation capabilities. DB2 UDB, Oracle and Informix are representative commercial products that feature object relational functionalities and 1 We are well aware that research into parameterized views is not altogether new [11, 4, 2, 7, 10]. But most of the e orts we are familiar with have focused their attention on logic based approaches to view parametrization, e.g. 11, 4, 2, 7] while others have concentrated on integrity maintenance through rule de nitions, e.g. 10] These latter approaches are essentially static, and most ....

.... into parameterized views is not altogether new [11, 4, 2, 7, 10] But most of the e orts we are familiar with have focused their attention on logic based approaches to view parametrization, e.g. 11, 4, 2, 7] while others have concentrated on integrity maintenance through rule de nitions, e.g. [10]. These latter approaches are essentially static, and most dynamic view parameterization approaches do not achieve our functionality. 2 The motivation and the idea of parameterized views, and relational uni cation were rst introduced in the context of GQL [6] 1 deserve mention. All three ....

Michael Stonebraker, Anant Jhingran, Jerey Goh, and Spyros Potamianos. On rules, procedures, caching and views in data base systems. In Proc. of the ACM SIGMOD, Atlantic City, NJ, May 23-25, pages 281-290, 1990.

....be done using physical or logical techniques. Physical caching is performed in terms of records, pages #i.e. blocks#, or static partitions of base tables. Logical caching is performed in terms of query results or subsets of query results #Roussopoulos and Kang 1986; Chen and Roussopoulos 1994; Stonebraker et al. 1990; Keller and Basu 1994; Dar et al. 1996##. Physical caching is used by most distributed systems today, including object oriented database systems, network #le systems, and database application systems such as SAP R#3. In contrast, many aspects of logical caching remain the subject of active ....

....This is, essentially, a knapsack problem, and we use the obvious heuristics of packing those tables with the highest value#size ratio #Horowitz and Sahni 1976#. #The same heuristics have also been used for data placement in Bubba #Copeland et al. 1988#, WATCHMAN #Scheuermann et al. 1996#, and in #Stonebraker et al. 1990##. This technique is demonstrated by the example shown in Table 1. In the example, the tables are sorted byvalue#size ratio. If the client s cache could hold 250 pages, then the maximal cached value would be obtained by caching tables A and B #i.e. a total value of 800 in this case#, and only ....

[Article contains additional citation context not shown here]

Stonebraker, M., Jhingran, A., Goh, J., and Potamianos, S. 1990. On rules, procedures, caching and views in data base systems. In Proc. ACM SIGMOD Conf. #Atlantic City, USA, April 1990#, pp. 281#290.

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M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in data base systems. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 281--290, 1990.

No context found.

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in database systems. In Proc. ACM SIGMOD, 1990.

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M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. In H. Garcia-Molina and H. V. Jagadish, editors, Proc. of ACM SIGMOD, pages 281--290, Atlantic City, NJ, May 1990.

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M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. In H. Garcia-Molina and H. V. Jagadish, editors, Proc. of ACM SIGMOD, pages 281--290, Atlantic City, NJ, May 1990.

No context found.

M.L. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedure, caching and views in database systems. In ACM SIGMOD Int. Conf. on Management of Data, pages 281--290, 1990.

No context found.

M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in data base systems. In Proc. ACM SIGMOD Symp. on the Management of Data, pages 281--290, 1990.

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M. Stonebraker, A. Jhingran, J. Goth and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. In Proc. of the ACM SIGMOD Inter national Conference on Management of Data, pages 281-290, Atlantic City, New Jersey, May 1990.

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M. Stonebraker, A. Jhingran, J. Goh, and S. Potamianos. On rules, procedures, caching and views in data base systems. In Proc. ACM SIGMOD Symp. on the Management of Data, pages 281--290, 1990.

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