J. Grant, J. Gryz and J. Minker et al. Semantic Query Optimization for Object Databases. In ICDE, pages 444-- 453, 1997.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... discovered using data mining techniques can be used for query optimization [HHCF96, Hsu96, HK96, Hsu97, HK98, HK00, Kin81b, LS95, MC96, SHKC93, YSP97, YS89] A number of heuristics have been proposed that take advantage of association rules in order to optimize queries semantically [Bel96, CGM90, GGMR97, GGZ01, Kin81a, SSS92] We refer briefly to the heuristics presented by Siegel et al. [SSS92] If a relation R in the query has a restricted attribute A and an unrestricted cluster index attribute B, then look for a rule where the restriction on A implies a restriction on B. This heuristic ....

....broader set of object oriented tools (ODB tools) Their optimizer takes advantage of the constraint introduction and constraint elimination heuristics, as well as of additional ones, e.g. reducing the scope of a query to a smaller subclass. These heuristics are presented in detail by Grant et al. GGMR97] Cheng et al. describe the implementation of two semantic optimization techniques, namely predicate introduction and join elimination, in DB2 Universal Database [CGK 99, GLQ99] After an input query is converted to an intermediate form called query graph model, it is transformed by a query ....

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J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Intl Conf on Data Engineering (ICDE), pages 444--453, 1997.

.... practicality range is extended even further when using the best plan rst heuristic, with reductions of 60 to 95 , up to optimizing queries with 14 joins, using 6 views ( 3,4,2] in gure 11) 6 Related work There are many papers that discuss semantic query optimization for relational systems([6, 13, 4] and the On a larger database, the bene ts of C B should be even more important. 10 references therein) The techniques most frequently used are [6] index introduction, join elimination, scan reduction, join introduction, predicate elimination and detection of empty answers. Of these, scan ....

....predicate elimination and detection of empty answers. Of these, scan reduction, predicate elimination and empty answers use boolean and numeric bounds reasoning of a kind that we have left out of our optimizer for now. We have shown examples of index and join introduction in section 2 and [13] contains a nice example of join introduction. The C B technique covers index and join introduction and in fact extends them by trying to introduce any relevant physical access structure. The experiments with EC2 and EC3 are already more complex than the examples in section 2 and [13] It also ....

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J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of ICDE, April 1997.

....that tries to extend the basic model of optimization is one that uses semantic knowledge about the logical schema: key constraints, functional dependencies, inclusion constraints such as foreign key constraints, inverse relationship constraints in OO schemas, etc. Semantic optimization [CGK 99, GGMR97, LS95, CGM90, FRV96, CD92] means finding rewritings, on the same logical schema, that are equivalent under the existing constraints with the original query. Typical transformations include join elimination, join introduction, predicate elimination or predicate introduction. These rewritings are, ....

....is possible Only when stratification is possible Figure 6.20: Features of C B based optimizers. 185 Conclusion and Future Work 7.1 Related Work There are many papers that discuss semantic query optimization for relational systems. An incomplete list includes [CGK 99, GGMR97, LS95, CGM90, SO89] and the references therein. The techniques most frequently used are [SO89] index introduction, join elimination, scan reduction, join introduction, predicate elimination and detection of empty answers. Of these, scan reduction, predicate elimination and empty answers use ....

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J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the 13th Int'l. Conference on Data Engineering, April 1997.

.... to eliminate dependent joins is implicit in Orion optimizations [26] and the type based approach of [19] This, and the use of precomputed ASR s appear in [28, 29] Precomputed join indexes are proposed in [46] An approach to semantic query optimization using a translation into Datalog appears in [13, 24]. The idea of using semantic constraints as rewrite rules is introduced and exploited systematically in [21, 22] When the physical schema contains only materialized relations, finding an execution plan is a generalization of the problem of answering queries using views ( 30] 38] At the ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the 13th Int'l. Conference on Data Engineering, April 1997.

....arena. In this paper, we will focus on this second view of meta data, as data explicitly stored in a database, featuring special description relationships with distinct instance level data. The description semantics can be profitably applied to problems such as semantic query optimization [19, 14, 8, 13, 21, 24] and deciding the containment or equivalence of queries under meta data interpreted as constraints (e.g. using the Chase [4, 25] problems that are of wide practical interest. Our argumentation builds on two simple concepts, the description pattern between classes and meta classes (where ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. "Semantic Query Optimization for Object Databases". In Proceedings of the 13th IEEE International Conference on Data Engineering (ICDE'97), pages 444--453, Birmingham, UK, Apr. 1997.

....correlate values of data attributes in large databases have been investigated for two main purposes. The first is to aid management and decision making in large companies with great amounts of data. The second relates to query optimization, by exploiting the semantic knowledge expressed in rules [2, 3, 6, 9, 10]. Siegel et al. 6] have proposed several heuristics to guide rule generation and so help to transform queries to more efficient forms. In this paper we investigate algorithms for applying two of these heuristics to optimize range queries. We express queries using OQL (Object Query Language) ....

....to both relational and object oriented database systems. There has been a lot of research on generating association rules and maintaining them in the presence of updates. Research has also focused on finding heuristics that take advantage of rules in order to optimize a query. Most of this work ([2, 3]) has considered integrity rules, rather than association rules with exceptions. Semantic optimization heuristics were also applied without considering indirect associations. In this paper, we implement algorithms that apply two optimization heuristics presented by Siegel et al. taking account of ....

J. Grant, J.Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In ICDE, pages 444--453, 1997.

....based on equivalences derived from method semantics. This semantics comes from the schema and is then translated by hand into rules that can be applied to expressions written in their algebra. As with [6] these rewrites are unconditional and there is no inference (Category (1) Grant et al. [14] employ a Datalog based scheme for object oriented databases that infers new integrity constraints from old explicitly declared constraints plus schema related information about functions (methods) This work employs inference, but only of new integrity constraints (i.e. conditions that hold of ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proceedings of the 13th ICDE Conference, pages 444--454, Birmingham, UK, April 1997.

....context of an arbitrary query with other language constructs. We also provide additional access methods for path expressions, and our optimization techniques are implemented within a complete DBMS. Similar comparisons can be drawn between our work and other recent OODB optimization work, e.g. GGMR97, KMP93, OMS95, SO95] Some recent papers have specified cost models for objectoriented DBMSs, e.g. BF97, GGT95] Object oriented databases typically support object clustering and physical extents, rendering many of these formulas inapplicable in our setting. Generalized path expressions. Other ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proceedings of the Thirteenth International Conference on Data Engineering, pages 444--454, Birmingham, UK, April 1997.

....to one run of the query. The bene t is much higher when the cost of optimization is amortized over multiple runs (as is often the case, e.g. OLAP environments) 6 Related work There are many papers that discuss semantic query optimization for relational systems. An incomplete list includes [7, 17, 24, 5, 29] and the references therein. The techniques most frequently used are [29] index introduction, join elimination, scan reduction, join introduction, predicate elimination and detection of empty answers. Of these, scan reduction, predicate elimination and empty answers use boolean and numeric bounds ....

....predicate elimination and detection of empty answers. Of these, scan reduction, predicate elimination and empty answers use boolean and numeric bounds reasoning of a kind that we have left out of our optimizer for now. We have shown examples of index and join introduction in section 2 and [17] contains a nice example of join introduction. The C B technique covers index 17 and join introduction and in fact extends them by trying to introduce any relevant physical access structure. The experiments with EC2 and EC3 are already more complex than the examples in section 2 and [17] It also ....

[Article contains additional citation context not shown here]

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the 13th Int'l. Conference on Data Engineering, April 1997.

....based on equivalences derived from method semantics. This semantics comes from the schema and is then translated by hand into rules that can be applied to expressions written in their algebra. As with [6] these rewrites are unconditional and there is no inference (Category (1) Grant et al. [14] employ a Datalog based scheme for object oriented databases that infers new integrity constraints from old explicitly declared constraints plus schema related information about functions (methods) This work employs inference, but only of new integrity constraints (i.e. conditions that hold of ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proceedings of the 13th ICDE Conference, pages 444--454, Birmingham, UK, April 1997.

....to which the residues could be directly attached. Research in SQO for queries involving an arbitrary nesting of union and join operations has been initiated in [64] and developed further in [45] 47] and [48] SQO can be extended to object oriented databases. An approach recently developed [50] transfers existing SQO techniques (for instance, based on residues) from the logic (or relational) to the object database model. The core of this technique is the transformation of an object schema into a relational schema, in such a way that the object semantics is reflected via integrity ....

....with that model. This meant, in particular, that many of the semanticbased techniques 15 designed for relational and deductive databases were not directly applicable to the object model; such techniques had to be developed specifically for the new model ( 91] and [9] It has been shown [50], however, that the existing techniques can be transferred from the relational to the object database model. The main idea of this approach is the transformation of an object schema into a relational schema in such a way that the object semantics is reflected in integrity constraints at the ....

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization in object databases. In Proceedings of ICDE, pages 444--453, Birmingham, UK, Apr 7--11 1997. IEEE Computer Science Press, Los Amitos, California.

....Gryz, 1996a] Godfrey and Gryz, 1996b] and [Godfrey et al. 1996] 22 This is the concept of top down query evaluation. 30 April 1997 ICs: Semantics and Applications Godfrey, Grant, Gryz, Minker p. 25 of 46 SQO can be extended to object oriented databases. An approach recently developed [Grant et al. 1997] transfers existing SQO techniques (for instance, based on residues) from the logic (or relational) to the object database model. The core of this technique is the transformation of an object schema into a relational schema, in such a way that the object semantics is reflected via integrity ....

....that many of the semantic based techniques 30 designed for relational and deductive databases were not directly applicable to the object model; such techniques had to be developed specifically for the new model ( Yoon and L. Kerschberg, 1993] and [Buchheit et al. 1994] It has been shown [Grant et al. 1997], however, that the existing techniques can be transferred from the relational to the object database model. The main idea of this approach is the transformation of an object schema into a relational schema in such a way that the object semantics is reflected in integrity constraints at the ....

Grant, J., Gryz, J., Minker, J., and Raschid, L. (1997). Semantic query optimization in object databases. In Proceedings of ICDE, Birmingham, UK.

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J. Grant, J. Gryz and J. Minker et al. Semantic Query Optimization for Object Databases. In ICDE, pages 444-- 453, 1997.

No context found.

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the Thirteenth International Conference on Data Engineering (ICDE'97), pages 444-- 453, 1997.

No context found.

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the Thirteenth International Conference on Data Engineering, pages 444-- 454, Birmingham, UK, April 1997.

No context found.

J. Grant, J. Gryz, J. Minker, and L. Raschid. Semantic query optimization for object databases. In Proc. of the Thirteenth International Conference on Data Engineering (ICDE'97), pages 444-- 453, 1997.

No context found.

J. Grant, J. Gryz, , J. Minker, and L. Raschid. Semantic query optimization for object databases. ICDE, November 1997.

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