Lin, J., Ozsoyoglu, Z.M., "Processing OODB Queries by O-Algebra", Proc. of CIKM,1996.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....and, more importantly, validated all the transformations. Their work was extended by Claussen et al. 1997] to include universal quanti cation. Our work proposes a rewriting system for complete unnesting, while their work considers algebraic equalities for some forms of unnesting. The work of Lin and Ozsoyoglu [1996] addresses nested queries in a di erent way. Nested OQL queries in their approach are rst translated into generalized path expressions that have enough expressive power to capture outer joins and grouping. This translation may be very inecient at the beginning due to a large number of redundant ....

Lin, J. and Ozsoyoglu, M. 1996. Processing OODB Queries by O-Algebra. In International Conference on Information and Knowledge Management (CIKM), Rockville, Maryland (Nov. 1996), pp. 134-142.

....validated all the transformations. Their work was extended by Claussen et al. CKMP97] to include universal quanti cation. Our work proposes a rewriting system for complete unnesting, while their work considers algebraic equalities for some forms of unnesting. The work of Lin and Ozsoyoglu [LO96] addresses nested queries in a di erent way. Nested OQL queries in their approach are rst translated into generalized path expressions that have enough expressive power to capture outer joins and grouping. This translation may be very inecient at the beginning due to a large number of redundant ....

J. Lin and M. Ozsoyoglu. Processing OODB Queries by O-Algebra. In International Conference on Information and Knowledge Management (CIKM), Rockville, Maryland, November 1996.

....validated all the transformations. Their work was extended by Claussen et al. CKMP97] to include universal quantification. Our work proposes a rewriting system for complete unnesting, while their work considers algebraic equalities for some forms of unnesting. The work of Lin and Ozsoyoglu [LO96, LZO98] addresses nested queries in a different way. Nested OQL queries in their approach are first translated into generalized path expressions that have enough expressive power to capture outer joins and grouping. This translation may be very inefficient at the beginning due to a large number ....

J. Lin and M. Ozsoyoglu. Processing OODB Queries by O-Algebra. In International Conference on Information and Knowledge Management (CIKM), Rockville, Maryland, November 1996.

....In particular, with the help of a theorem prover, an optimizer does not require validation in a form of a formal proof each time a new algebraic operator or a new rewrite rule is introduced. We are planning to experiment along this direction in the near future. The work of Lin and Ozsoyoglu [16] addresses nested queries in a different way. For each nested query, a method is created and the inner query is replaced by a call to this method. This is a nice approach if the goal is to translate a language that allows query nesting to a language or algebra that does not allow it. But of course ....

J. Lin and M. Ozsoyoglu. Processing OODB Queries by O-Algebra. In International Conference on Information and Knowledge Management (CIKM), Rockville, Maryland, November 1996.

....techniques to process GVISUAL queries involving presentations. The contributions of this paper are listed below. 1) Translating GVISUAL queries into an operator based language: GVISUAL allows users to specify paths using icons corresponding to temporal operators Next, Connected and Until. In [LiOz 96] wehave described an object algebra language, called O Algebra, for processing object oriented queries. O Algebra is an internal algebra, designed for an internal implementation (i.e. it is not for users to use directly) In this paper, we (a) give an internal, table based representations of ....

....three temporal algebra operators MakeNext, MakeConnect and MakeUntil that use CO s and are algebraic, set at a time versions of the GVISUAL operators Next, Connected and Until. c) Wegive a direct translation from GVISUAL to O Algebra. 2) Implement the new O Algebra operators efficiently: In [LiOz 96] efficient O Algebra implementations are discussed# therefore, here, we only consider the new graph operators of O Algebra. Observing that presentations (graphs) are probably sparse and not very large (possibly, graphs with less than 50 nodes) we (a) propose the nodecode system which is based ....

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Lin, J., Ozsoyoglu, Z.M., "Processing OODB Queries by O-Algebra", Proc. of CIKM,1996.

....that deliver presentations [BalO 97] and playout agents that play multimedia presentations. ViSiOn clients, registered and controlled by an administration server [Yao 97] provide the GVISUAL interface to users, and translate a GVISUAL query directly into an object algebra, called O Algebra [LiOz 96, LXO 97] Three new operators are added to O Algebra to evaluate GVISUAL queries [LeOz 97, BBL 97] namely, X next , X connect , and X until , that correspond to the set at a time evaluations of X (next) C(connected) and U(until) respectively, of GVISUAL. A ViSiOn client translates a ....

Lin, J., Ozsoyoglu, Z.M., "Processing OODB Queries by O-Algebra", Proceedings of CIKM, 1996.

....corresponding to temporal operators Next, Connect and Until. We extend O Algebra This research is supported by the National Science Foundation Grants IRI 92 24660, IRI 96 31214 and CDA 95 29503 V: Promo Song A: V: T T Cuyahoga Title: River Wild Life State Parks A:Four Seasons Figure 1. 1 ( LiOz 96] LXO 97] an algebraic language, with the corresponding temporal operators, MakeNext, MakeConnect and MakeUntil that are algebraic, set at a time versions of the GVISUAL operators Next, Connected and Until. We then give a translation from GVISUAL into the (extended) O Algebra. 2) implementing ....

....Graphs In this paper, we use class extents Pres Graphs, Pres Nodes, Pres Edges, Streams, Frames, C Objects for the classes Pres Graph, Pres Node, Pres Edge, Stream, Frame and C Object, respectively. To internally represent class extents, we use tables, called CO s (collection of objects) LiOz 96] LXO 97] Each CO has only one level of nesting, and we map (possibly multilevel) objects of each class into one or more CO s. Object id s (oid s) of objects are retained in CO s. Example 2.1. Assume that we have the two presentation graphs given in Figure 2.2 (a) Then, the corresponding CO s ....

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Lin, J., Ozsoyoglu, Z.M., "Processing OODB Queries by O-Algebra", Proc. of CIKM, 1996.

....the conversion from SOQL to O Algebra. The conversion from OQL to SOQL is discussed in section 4. In section 5, a complete example illustrating processing and optimizing OQL queries using O Algebra is presented. Section 6 is the conclusion. Due to the space limitations the reader is referred to [LO95a, LO95b] for the complete set of OAlgebra laws, and formal transformation from OQL queries to O Algebra. 2 O Algebra O Algebra supports the following types: 1. Base type: integer, string, date, real, etc. 2. Ref 1 type: ref( where is an object type. 3. Bulk data type: bag( set( list( ....

....i.e. S[x] A1: Ak [y ] and 3)paths with null values, i.e. S[x] A1: Ak [y j y ] The difference among them is in the type of y, which is the scalar value, is the bulk data value, or may have the null value for above three cases, respectively. The formal semantics of the paths is given in [LO95b]. In SOQL, the functionality of nested queries is provided by methods. To refer to the COs constructed by the methods we use paths called calling paths. Before giving an example to illustrate calling paths, we first define methods in SOQL. Methods : All nested queries as well as define blocks in ....

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J.Lin and Z.M.Ozsoyoglu, "Processing OODB queries by O-Algebra," Technical Report, Case Western Reserve University, Computer Eng. & Sci. Dept., 1995.

....to the sequence operators of OQL, GOQL uses the temporal operators next, until and connected for querying paths and sequences, so that queries involving relative ordering of sequence elements are supported. For processing, GOQL queries are translated into an operator based language, O Algebra [LiOz96] extended with new operators. O Algebra is an object algebra designed for processing object oriented database (OODB) queries. O Algebra offers a small set of operators, and most of them are similar to their counterparts of the extended relational algebra. Operands of O Algebra are sets of ....

....of the extended relational algebra. Operands of O Algebra are sets of objects with a uniform structure each object consists of an Oid and a tuple of at most one level of nesting. In processing, front end objects are mapped to internal type objects. A general procedure is presented in [LiOz96, LZO97] to convert OQL queries into O Algebra expressions, which also reduces all nested queries during transformation. Since GOQL is an extension of OQL, to deal with path and sequence expressions, O Algebra is extended with three temporal operators Theta Next ; Theta Connected , and ....

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Lin, J., Ozsoyoglu, Z.M., "Processing OODB Queries by O-Algebra", Proceedings of CIKM, 1996.

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