P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Proc. Int. Conf. on Extended Database Technology (EDBT), pages 169--187, Venice, 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....will show an increased interest in optimization issues in the context of object oriented DBMSs. The contribution of this paper can be seen as one important piece in the mosaic of performance enhancement methods for object oriented database applications. Of course as some authors point out, e.g. [9] there are vast similarities between query processing in relational DBMSs and object bases. Therefore, the large body of knowledge of relational optimization techniques (e.g. 8, 16] can serve as a basis. However, the full tential of the object oriented paradigm can only be exploited for ....

....design of such a complex transformation system. This enables the designer to experiment with dif ferent search heuristics to limit the number of transforma tions that have to be considered to derive a near optimal evaluation plan. Related work on object oriented query processing is re ported in [9, 12] where a graph based approach was chosen for optimizing a limited class of queries, i.e. only queries that correspond to an acyclic graph are consid ered. Also, the cited work does not take general access support relations into account it is based solely on (binary) indexes as known in ....

B. P. Jeng, D. Woelk, W. Kim, and W. L. Lee. Query processing in distributed ORION. In Proc. of the EDBT (Eztending Data Base Technology) Conf., Venice, Italy, Mar 1990.

....[CGK 99] reports on join elimination in star queries that are still less complex than our experiments with EC2. Examples of SQO for OO systems appear in [SZ89a, CD92, Clu91, BK93, FM95b, FM95a, GGMR97, CZ98] Use of referential integrity constraints to eliminate dependent joins is implicit in [JWKL90, CD92, KM90a, KM90b] A general framework for SQO using rewrite rules expressed 186 using OQL appears in [FRV96, Flo96] Techniques for using materialized views in query optimization are discussed in [YL87, TSI94, CKPS95, Flo96, FRV96, TSI96, Ba98] A survey of the area appears in [Lev] For ....

P. Jeng, D. Woelk, W. Kim, and W. Lee. Query processing in distributed orion. In Proc. EDBT, Venice, Italy, March 1990. 197

.... continuing with OODB optimizations as in the work of Cluet, Zdonik, Maier, Fegaras and others [42, 43, 19, 18] and in fact including the very comprehensive work by Beeri and Kornatzky [8] Use of referential integrity constraints 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 ....

P. Jeng, D. Woelk, W. Kim, and W. Lee. Query processing in distributed orion. In Proc. EDBT, Venice, Italy, March 1990.

....1995. The work of Brodsky was supported in part by NSF RIA grant IRI 9409770, and by Office of Naval Research under prime grant No. N00014 94 1 1153. The work of Wang was supported in part by NSF RIA grant IRI 9409769, and by NSF grant BIR 9404831 [S86] ENCORE [Z89] O2 [D90] ORION [JWKL90], POSTGRESS [SRH90] and Illustra) Object Store [OHMS92] Open OODB [BKG93] and UniSQL. Surprising is that while these systems targeted to a large extent the above mentioned application realms, little was done to address the problem of optimization in the presence of expensive predicate and ....

B. Jenq, D. Woelk, W. Kim and W. Lee, "Query Processing in Distributed Orion", Proc. of the 1990 Int. Conf. on Extending Database Technology, 1990. 19

.... on algebraic rewriting rules is inspired on relational [20] and object oriented query optimization (e.g. 37] 16] This is not surprising, since it has been noted in the context of object oriented databases that relational query optimization can be well extended to complex structures ( 33] [24]) However, the differences between the problem we treat here and conventional query optimization, which we listed in the Introduction, lead to rather different solutions. Optimizing path expressions Evaluating queries on the Web has some points of contact with the problem of optimizing ....

.... a large body of research about query processing has been devoted to their optimization: also in this case, the focus is on transforming pointer chasing operations which are considered rather expensive into joins of pointer sets stored in auxiliary access structures, such as class extents [24], access support relations [25] and join indices [38] 41] Although it may seem that a similar approach may be extended to the Web, we show that the more involved nature of access paths in Web sites and the absence of ad hoc auxiliary structures introduces a number of subtleties. We compare two ....

B. P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Int. Conf. on Extending Database Technology (EDBT'90), Venezia, Lecture Notes in Computer Science 416, 1990. 169--197.

....instead of on the server. Further, the hybrid shipping approach can benefit from using client disk resources in parallel with server disk resources. The hybrid approach is used in some database products such as UniSQL, application systems such as SAP R 3, and research prototypes such as ORION2 [23]. This approach is also used by distributed wrapper based heterogenous systems such as DISCO [40] Garlic [15, 30] and Mariposa [34, 36] The ADMS project [31] also uses hybrid shipping, although it requires that all aggregation, duplicate elimination, and sorting be done at the client during ....

B. Paul Jenq, Darrel Woelk, Won Kim, and Wan-Lik Lee. Query processing in distributed orion. In F. Bancilhon, C. Thanos, and D. Tsicritzis, editors, Advances in Database Technology--EDBT'90, pages 169--187, Venice, Italy, March 1990.

....nested results, an essential feature found in these languages is the nesting of queries, i.e. the embedding of a query into another query. The optimization of object oriented (oo) queries has been intensively studied using algebraic rewriting [4, 7, 23, 24, 25] or rewriting of path expressions [7, 13, 14]. However, in spite of the importance of nested queries, we do not know of any research on their optimization. Nested queries in the oo context are usually translated into nested algebraic expressions which are evaluated through rather inefficient nested loops. To a lesser extent, relational ....

P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Proc. Int. Conf. on Extended Database Technology (EDBT), Venice, 1990.

....queries often involve pointer chasing operations through the different components of the database objects. This kind of operations may imply numerous input output operations (I O) One way to minimize I O is to consider class extents in order to transform navigation into algebraic join operations [13, 15]. Another technique consists in having a specialized module in the optimizer whose task is to avoid an object at a time reading of the various components needed in the evaluation of the query [14] Secondly, a component of an object may be a nested structure. This leads, for instance, to ....

....supports heuristics in order to reduce the optimization rewriting phase. There exist two main approaches to query rewriting in the object oriented context: the algebraic approach [17, 6, 18] and the one, that we call the type based approach, which transform pointer chasing into join operations [13, 15]. We unify these two appoaches in one formalism. We show that it is just the lack of type information (membership to class extents) that makes it impossible to perform type based transformations using algebraic equivalences. Accordingly, we extend the algebraic approach by reducing and typing the ....

[Article contains additional citation context not shown here]

P. Jenq, D. Woelk, W. Kim, and W. Lee. Query Processing in Distributed ORION. In proc. EDBT, Venice, Italy, March 1990.

....such advanced query processing systems. 1.1 Caching and Query Optimization Recent activity in the development of distributed database architectures has focused on allowing the #exible and dynamic placementofquery operators #e.g. selects, joins, aggregates, etc. # at various sites in the network #Jenq et al. 1990; Franklin et al. 1996; Stonebraker et al. 1996; De#loch et al. 1998; Mayr and Seshadri 1999; Rodgriguez Martinez and Roussopoulos 2000#. In such systems, query operators can be placed at sites in a way that minimizes expected communication costs, execution time, or other metrics. These decisions ....

....among clients and servers. At present, most commercial client server database systems #e.g. Oracle 8# do not 6 # Kossmann, Franklin, Drasch provide the #exibilitytochoose among these options. A #exible approach, however, has become increasingly popular in experimental systems such as ORION 2 #Jenq et al. 1990#, KRISYS #De#loch et al. 1998#, Mariposa #Stonebraker et al. 1996#, Predator #Mayr and Seshadri 1999#, and MOCHA #Rodgriguez Martinez and Roussopoulos 2000#, and has been integrated into an extended version of the SHORE storage manager #Carey et al. 1994# as part of the work described here. In ....

Jenq, B., Woelk, D., Kim, W., and Lee, W. 1990. Query processing in distributed ORION. In Proc. of the Intl. Conf. on Extending Database Technology #EDBT# #Venice, 36 # Kossmann, Franklin, Drasch Italy, March 1990#, pp. 169#187.

....plans in multidatabase systems. This language lacks the capability to specify the execution coordination among local databases. 5] proposed a message based approach to retrieve data in class composition hierarchies. However, the integration of partial results from subqueries was not supported. [13] proposed query processing strategies in the distributed object database system. However, the proposed strategies only dealed with queries on complex objects without a discussion on class hierarchies. Moreover, semantic discrepencies which exist in multiple object database systems were not ....

B. Paul Jenq, Darrell Woelk, Won Kim, and Wan-Lik Lee. "Query Processing in Distributed ORION". MCC Technical Report Number: ACA-ST-035-89, pages 1--26, Jan 1989.

....expressions. The classical algebraic approach [Codd70, Shaw90, Vandelberg91, Steenhagen94] permits a decomposition of a long path in shorter binary paths. Efficient algorithms for traversing binary paths (i.e. join algorithms) are presented and compared in [Shekita90] A graph traversal approach [Jenq90] enables a long path to be traversed forward and backward. A variant approach is the typed algebra [Cluet92] which allows the Jenq et al. traversals to be described as binary algebra expressions. Another approach uses path indexes to directly achieve a whole navigation [Kemper90] A more general ....

....(the rule is then denoted SEq1) and pipelined (the rule is then denoted PEq1) programs. The rule uses the DefCol function to explicitly name abstract collections obtained dynamically. The importance of join commutativity was confirmed in [Blakeley93] for queries against a single target class [Jenq90]. More than explicit joins, the quantifier expressions represent a sequence of select, join, and project operators, which can be evaluated as a whole [Cluet92] Equivalence P SEq1 if Ck is not the result of a DefCol function DefCol(Ck,g(ci) for some g in F: ForAll(Ci, lci p1(ci) ForAll(Ck, ....

Jenq B. P., Woelk D., Kim W., Lee W., "Query Processing in Distributed ORION", Intl. Conf. EDBT, Venice, Italy, March 1990.

....which can be executed in local sites in parallel [3] 20] used semijoin to reduce the cost of data transmission. Determining the join sequence for reducing the transmission cost was studied in [6] Query processing strategies for homogeneous distributed object database systems were discussed in [10]. None of the previous papers considered the missing data due to schema conflicts. The schema and domain incompatibilities in the multidatabase systems were considered in [11] and [16] The approaches of partial values and probabilistic partial values were proposed to solve the schema integration ....

B.P. Jeng, D. Woelk, W. Kim, and W.L. Lee, Query Processing in Distributed ORION, MCC Technique Report Number: ACA-ST-03589, (1989) pp.1-26.

....than what we have considered. 7] reports on join elimination in star queries that are still less complex than our experiments with EC2. Examples of SQO for OO systems appear in [28, 10, 9, 3, 14, 13, 17, 8] Use of referential integrity constraints to eliminate dependent joins is implicit in [19, 10, 20, 21]. A general framework for SQO using rewrite rules expressed using OQL appears in [16, 15] Techniques for using materialized views in query optimization are discussed in [33, 31, 6, 15, 16, 30, 12] A survey of the area appears in [22] From our perspective, the work on join indexes [32] and ....

P. Jeng, D. Woelk, W. Kim, and W. Lee. Query processing in distributed orion. In Proc. EDBT, Venice, Italy, March 1990.

....are not sufficient and require considerable re design. There has been extensive work on object oriented and extensible database processing, which led to the development of research prototypes as well as commercially available systems, such as Starburst [S86] ENCORE [Z89] O2 [D90] ORION [JWKL90], POSTGRESS [SRH90] and Illustra) Object Store The work of Brodsky was supported in part by NSF RIA grant IRI 9409770, and by Office of Naval Research under prime grant No. N00014 94 1 1153. y The work of Wang was supported in part by NSF RIA grant IRI 9409769, and by NSF grant IRI 1 ....

B. Jenq, D. Woelk, W. Kim and W. Lee, "Query Processing in Distributed Orion", Proc. of the 1990 Int. Conf. on Extending Database Technology, 1990.

....paradigm. Such configurations are normally referred to as multidatabase or federated database systems. Current advances in multidatabases show the applicability of object oriented data models for the purpose of integrating diverse component data sources and supporting interoperability [19, 20]. The technical approach to object oriented multidatabase interoperability is based on an amalgamation of object oriented database concepts and distributed data management methodologies. 3 Middleware Facilities Most successful architectural approaches to distributed computing use middleware ....

B.P. Jenq, D. Woelk, W. Kim, W. Lee "Query Processing in Distributed Orion", EDBT 90: Int'l Conf. on Extending Database Technology, May 1990.

.... on algebraic rewriting rules is inspired on relational [14] and object oriented query optimization (e.g. 28] 12] This is not surprising, since it has been noted in the context of object oriented databases that relational query optimization can be well extended to complex structures ( 24] [17]) However, the differences between the problem we treat here and conventional query optimization, which we listed in the Introduction, lead to rather different solutions. Optimizing path expressions Evaluating queries on the Web has some points of contact with the problem of optimizing ....

.... a large body of research about query processing has been devoted to their optimization: also in this case, the focus is on transforming pointer chasing operations which are considered rather expensive into joins of pointer sets stored in auxiliary access structures, such as class extents [17], access support relations [18] and join indices [29] 31] Although it may seem that a similar approach may be extended to the Web, we show that the more involved nature of access paths in Web sites and the absence of ad hoc auxiliary structures introduces a number of subtleties. We compare two ....

B. P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Int. Conf. on Extending Database Technology (EDBT'90), Venezia, Lecture Notes in Computer Science 416, 1990. 169--197.

.... oriented query processing focus mainly on the structural part of object oriented data models and do not take account of the much richer semantics methods can carry and which have to be taken into account for really efficient query processing in non standard applications. Thus conclusions as in [32] are drawn: In retrospect, the extent of similarities between relational and object oriented query processing should not have come as a surprise, if we recognize that, regardless of data models, query processing is essentially a process of mapping a declarative query expression into a sequence of ....

....already developed into a stable framework for query languages on the structural part of object oriented databases, for overviews see [9] 27] In [43] an architecture closely related to relational architectures is proposed. Implementations that follow these proposals are found in Orion Itasca [5][32], O2 [4] 14] 16] OSCAR [26] and Cocoon [40] Work concentrating on the impact of methods in the framework of object oriented query processing is somehow rare. Some theoretical aspects are covered in [6] An approach suggesting precomputation of methods for indexing is described in [10] A ....

W. Kim, B.P. Jenq, D. Woelk, W.-L. Lee: "Query Processing in Distributed ORION", Proceedings of the International Conference on Extending Database Technology (EDBT '90), Venice, Italy, 1990.

.... based on algebraic rewriting rules is inspired on relational and object oriented query optimization (e.g. 18] 5] This is not surprising, since it has been noted in the context of object oriented databases that relational query optimization can be well extended to complex structures ( 14] [7]) However, the differences between the problem we treat here and conventional query optimization, which we listed in the Introduction, lead to rather different solutions. Optimizing path expressions Evaluating queries on the Web has some points of contact with the problem of optimizing ....

....a large body of research about query processing has been devoted to their optimization. In this research, the focus is on transforming pointer chasing operations which are considered rather expensive into joins of pointer sets stored in auxiliary access structures, such as class extents [7], access support relations [8] and join indices [19] 20] Although it may seem that a similar approach may be extended to the Web, we show that the more involved nature of access paths in Web sites and the absence of ad hoc auxiliary structures introduces a number of subtleties. We compare two ....

B. P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In EDBT'90.

....terme multi valu e t 2 . En utilisant cette connaissance, il est possible de remplacer dans l expression d un terme la jointure fonctionnelle d efinie par t 1 par une jointure explicite impliquant la collection t 2 . Ce type de r e ecriture g en eralise la r e ecriture bas ee sur les types ( CD92, JWKL90] Avec la r e ecriture bas ee sur les types, l assertion d appartenance utilis ee est celle inh erente au mod ele objet: la valeur d un terme t de type c (c etant une classe) appartient a l extension de la classe c 8 . Les assertions d equivalence d efinies ici g en eralisent ce genre ....

....qui propose ce m elange d algorithmes [GGT96] 7 Travaux connexes La plupart des produits SGBDO comme ObjectStore et GemStone font peu d optimisation, et se bornent a exploiter les chemins d acc es existants sans faire de transformation alg ebrique. Les principales exceptions sont Orion [JWKL90] Epoq [SZ90] GOM [KMP93] O2 [VDD 90] et Volcano [GM93] 7.0.4 Orion Orion [JWKL90] fut le premier SGBDO a introduire des techniques d optimisation de requetes. Le langage de requetes, bas e sur Lisp, est simple. L optimiseur Memory Size (KBytes) Response Time (s) 0 500 1000 1500 2000 ....

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B.P. Jenq, D. Woelk, W. Kim, and W.-L. Lee. Query processing in distributed ORION. In Proc. EDBT, Venice, Italy, 1990.

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P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Proc. Int. Conf. on Extended Database Technology (EDBT), pages 169--187, Venice, 1990.

No context found.

B. P. Jeng, D. Woelk, W. Kim, and W. L. Lee. Query processing in distributed ORION. In Proc. of the EDBT (Extending Data Base Technology) Conf., Venice, Italy, Mar 1990.

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B. Paul Jenq, Darrel Woelk, Won Kim, and Wan-Lik Lee. Query Processing in Distributed ORION. Technical report, MCC, January 1989. In [ita90]. 26 pages. MCC TR # ACA-ST035 -89.

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P. Jenq, D. Woelk, W. Kim, and W. Lee. Query processing in distributed ORION. In Proc. Int. Conf. on Extended Database Technology (EDBT), pages 169--187, Venice, 1990.

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B. Paul Jenq et al. Query Processing in Distributed ORION. In EDBT, pages 169--187, 1990.

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B. P. Jeng, D. Woelk, W. Kim, and W. L. Lee. Query processing in distributed ORION. In Proc. of the EDBT (Extending Data Base Technology) Conf., Venice, Italy, Mar 1990.

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