B. Subramanian, T. Leung, S. Vandenberg, and S. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering, pages 80-89, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... molecular biology databases, the language needs to have expressive power beyond regular sets [4] hence, more expressive grammatic formalisms have been employed in computational biology [15, 24] In addition to data extraction features, the string language needs also data restructuring constructs [11, 19, 28]. For example, given two unary relations, one might want to concatenate each string from one of the relations with a string from the other relation, as opposed to merely taking the Cartesian product of the two relations; Example 1 below shows how to do it in our language. Both of these goals can ....

B. Subramanian, T. Leung, S. Vandenberg, and S. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering, pages 80-89, 1995.

....18, 24] Most of these algorithms focus on comparing two trees based on various distance metrics. Chawathe et al. 7, 8, 9] studied the tree matching problem in the context of change detection for structured and semistructured data. There are also e orts spent in the development of query languages [2, 14, 16, 19, 20] and query processing techniques [10] for trees, with applications to XML and object oriented database management. In this paper we propose a new approach for approximate search among unordered labeled trees. Our problem, denoted the approximate nearest neighbor search (ANN) problem for unordered ....

B. Subramanian, T. W. Leung, S. L. Vandenberg, and S. B. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In Proceedings of the IEEE International Conference on Data Engineering, pages 80-89, 1995. 18

....have been proposed. The W3C working group on XML Query has recently issued an algebra document [1] The focus of this algebra is to provide a formal semantics for XQuery [2] It is not suitable for set oriented processing. There are a few examples of tree targeted algebras. The Aqua project [3], which focuses on the identification of pattern matches and their rewriting in the style of grammar production rules. A grammar based algebra [4] shown equivalent to a calculus, for manipulating tree structured data using production rules. An extension of a relational algebra [6] that uses ....

B. Subramanian, T. W. Leung, S. L. Vandenberg, S. B. Zdonik. The AQUA approach to querying lists and trees in objectoriented databases. In Proc. ICDE, 1995.

....coherence and consistency. Fifth, we allow for interval probabilities over solution sets of temporal constraints, while their work allows only for precise point probabilities over intervals of time points. Our work is also related to data models and algebraic operations for complex objects [1, 37, 44, 41, 40, 6]. Our work is a strict extension of the algebra for complex values presented by Abiteboul et al. 1] As in the case of Shaw and Zdonik [37] Vandenberg and DeWitt [44] and Boncz et al. 6] our data model supports the type constructors for sets and tuples on elementary datatypes. Like them, we ....

....topic of future research. The nested relational algebra described in [41] is a functional language for complex objects, which also allows for defining the high level algebraic operations of selection, projection, Cartesian product, intersection, and difference [41] Finally, Subramanian et al. [40] describe an object oriented query algebra for lists and trees. They also present a predicate language for lists and trees, which supports order sensitive queries, as it is based on pattern matching. Such algebraic operations are in some sense related to our extraction operation, which extracts a ....

B. Subramanian, T. W. Leung, S. L. Vandenberg, and S. B. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In Proceedings ICDE-95, pages 80--89. IEEE Computer Society, 1995.

....(DM) course and that have a professor teaching a database (DB) course. This query could be expressed by a tree pattern, as shown in Figure 1(c) The tree pattern is contained in the tree in Figure 1(b) and hence the university in Figure 1(b) would be returned as an answer to the query. AQUA Query [62, 86, 87]. AQUA was an object oriented data model developed at Brown University for supporting bulk types such as trees, sets, bags, etc. Consider, for example, the family tree in Figure 2(a) 86] Each node represents a person object. Each edge stands for the relationship a child of and a path in the ....

....1(b) and hence the university in Figure 1(b) would be returned as an answer to the query. AQUA Query [62, 86, 87] AQUA was an object oriented data model developed at Brown University for supporting bulk types such as trees, sets, bags, etc. Consider, for example, the family tree in Figure 2(a) [86]. Each node represents a person object. Each edge stands for the relationship a child of and a path in the tree stands for the relationship a descendent of . Now consider the query supported by the select operator in AQUA [86] Find all nodes (persons) who are ancestors of Alex and also ....

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B. Subramanian, T. W. Leung, S. L. Vandenberg, and S. B. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In Proceedings of the IEEE International Conference on Data Engineering, pages 80-89, 1995.

....this data model. Tree pattern matching is a well studied problem, with notions of regular expressions, grammars, etc. being extended from strings to trees (cf. 14, 21] These ideas have been incorporated into an object oriented database, and an algebra developed for these in the Aqua project [30]. The focus of this algebra is the identi cation of pattern matches, and their rewriting, in the style of grammar production rules. Our notion of tree pattern and witness trees follows Aqua in spirit. However, Aqua has no counterpart for most TAX operators. In the context of the Web, we should ....

B. Subramanian, T. W. Leung, S. L. Vandenberg, S. B. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In Proc. ICDE, 1995.

....gives the user the possibility to define predicates of her own using AQL. Other related work has been carried out in the study of complex object databases and sequence databases. These suggestions include for example the extended NF 2 model [19] the SEQ model [22] and the AQUA data model [25]. Implementations based on these suggestions have also been reported [23, 28] The di#erence between these approaches compared to ours is that they are interested in developing a new data model supporting ordered data types like lists of records while our focus is in the string fields of the data ....

Subramanian, B., Leung, T., Vandenberg, S., and Zdonik, S. The AQUA approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering (1995), pp. 80--89.

.... in the AllSubStream(s) need to be examined to evaluate the query, a query processor should optimize the evaluation of the function AllSubStream(s) This optimization can be accomplished by using a filtering process such as the optimization technique used in the string and list retrieval [SLVZ95] For example, if the beginning or ending snapshot is required to satisfy certain constraints, only those sub streams that begin or end with snapshots satisfying the constraints are examined. Due to its high execution cost, examining all candidate substreams in the AllSubStream(s set should ....

B. Subramanian, T. W. Leung, S. L. Vandenberg, and S. B. Zdonik. The aqua approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering, 1995.

....with optimizing rewrite systems. A specific translation technique for the decomposed model can be found in [28,45] For supporting object oriented systems, database researchers have tried to repeat the successes in the relational field by proposing a number of object oriented query algebras [41,8]. They offer a nested object data model for supporting complex objects and support multiple collection types like Set, List and Bag. These languages were designed as input languages for algebraic OQL query SELECT year, sum(total) FROM ( SELECT price tax AS total, year(item.order.day) AS year ....

B. Subramanian, T.W. Leung, S.L. Vandenberg, and S.B. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In Proc. ICDE Conf., pages 80--89, March 1995.

....of objectoriented databases and their query optimizers. We propose the stack based approach to query languages as an adequate framework aiming at the same goals. 1 Introduction Object algebras are proposed as tools to formalise object oriented databases and their query languages (QLs) see [AbFi95, AlAr93, BaWi94, CDV88, Clue89, ClDe92, ClDe94, DGG94, GZC89, HFLP89, KeMa94, LMSVVZ93, Liu93, PoSm94, ShZd89a, ShZd89b, ShZd90, StOz90, SZLV93, SLVZ95, VaDe91], and many others. They are claimed to be well suited to solve query optimisation problems. In this paper we carry out a critical analysis of this research activity. There are two principal reasons motivating our work. First, we see in these algebras severe flaws, which cause doubts concerning ....

B. Subramanian, T.W. Leung, S.L. Vandenberg, S.B. Zdonik. The AQUA Approach to Querying Lists and Trees in Object-Oriented Databases. Proc. of 11-th Intl. Conf. on Data Engineering, Taipei, Taiwan, March 6-10, 1995, pp. 80-89

.... biology databases, the language needs to have expressive power beyond regular sets [3] hence, more expressive grammatic formalisms have been employed in computational biology [4, 6, 16, 25, 26] In addition to data extraction features, the string language needs also data restructuring constructs [12, 20, 31]. For example, given two unary relations, one might want to concatenate each string from one of the relations with a string from the other relation, as opposed to merely taking the Cartesian product of the two relations; Example 1 below shows how to do it in our language. Both of these goals can ....

B. Subramanian, T. Leung, S. Vandenberg, and S. Zdonik. The AQUA approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering, pages 80--89, 1995.

....the potential of object algebras, in the proposed forms, as formal and intellectual tools for the development of objectoriented databases and their query optimizers. 1 Introduction Object algebras are proposed as tools to formalise objectoriented databases and their query languages (QLs) see [AlAr93, BMG93, CDV88, Clue89, ClDe92, ClDe94, DGG94, GZC89, HFLP89, KeMa94, LMSVVZ93, PoSm94, ShZd89a, ShZd89b, ShZd90, StOz90, SZLV93, SLVZ95, VaDe91], and many others. They are claimed to be well suited for query optimization. In this paper we carry out a critical analysis of this research activity. There are two principal reasons motivating our work. First, we see in these algebras severe flaws, which cause doubts concerning their ....

B. Subramanian, T.W. Leung, S.L. Vandenberg, S.B. Zdonik. The AQUA Approach to Querying Lists and Trees in Object-Oriented Databases. Proc. 11th Conf. on Data Engineering, 1995, pp. 80-89.

....gives the user the possibility to define predicates of her own using AQL. Other related work has been carried out in the study of complex object databases and sequence databases. These suggestions include for example the extended NF 2 model [19] the SEQ model [22] and the AQUA data model [25]. Implementations based on these suggestions have also been reported [23, 28] The difference between these approaches compared to ours is that they are interested in developing a new data model supporting ordered data types like lists of records while our focus is in the string fields of the data ....

Subramanian, B., Leung, T., Vandenberg, S., and Zdonik, S. The AQUA approach to querying lists and trees in object-oriented databases. In IEEE International Conference on Data Engineering (1995), pp. 80--89.

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