H. Meuss, K. Schulz, and F. Bry. Towards Aggregated Answers for Semistructured Data. In Proc. 8th Int. Conf. on Database Theory, 2001.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....needed when XML is used as a data model for databases. As discussed in [13, 68, 3] and in the rst section of this paper, this is a very promising direction of research. A number of database projects have investigated various aspects of using XML as a data model for databases, see in particular [1, 2, 9, 20, 30, 15, 21, 43, 11, 16, 32, 33, 31]. The articles [28, 6] explain and compare query languages proposed for XML. 2.9.1 XML QL, YATL, and Lorel From the database community, three languages inspired by SQL have been proposed for querying XML data: XML QL [15] YATL [12] and Lorel [2] Demos of these languages are available at [58, ....

H. Meuss et al. Towards Aggregated Answers for Semistructured Data. Technical report, Institute for Computer Science and Center for Computational Linguistic, University of Munich, 2000. Submitted for publication, http://www.pms.informatik.unimuenchen. de/publikationen/PMS-FB/PMS-FB-2000-6.ps.gz.

No context found.

H. Meuss, K. Schulz, and F. Bry. Towards Aggregated Answers for Semistructured Data. In Proc. 8th Int. Conf. on Database Theory, 2001.

No context found.

H. Meuss, K. U. Schulz, and F. Bry. "Towards Aggregated Answers for Semistructured Data". In Proc. of the 8th International Conference on Database Theory (ICDT'01), pages 346--360, 2001.

....and 10 hotels with 16 occurrences of the string tv in total. The first city contains two matching hotel elements, the second city eight. Complete Answer Aggregates can be computed very efficiently due to their compact (polynomial sized) representation of an exponential number of answers (cf. [6, 7]) Queries are evaluated pathwise with the help of a dedicated path index structure [5] Evaluation is based on a dynamic programming algorithm that guarantees that every database node is touched at most a constant number of times. 3 Exploring Complete Answer Aggregates The design of the user ....

H. Meuss, K. U. Schulz, and F. Bry. Towards aggregated answers for semistructured data. In ICDT'01, Int. Conf. on DB Theory. Springer, 2001.

....queries in SSD is used by XPath [18] The difference between XPath and our localization approach is that the localization is done by a path instead of a tree and the result usually is a set of nodes instead of a combined answer. Inspirations for the topic have originated from the paper [10], where matching for elementary data trees with aggregated answers has been proposed. However, our work goes beyond and presents an enriched SSD data model based on adding grouping constructs, i.e. aggregated trees also for databases and patterns. A collection of tree matching problems, called ....

H. Meuss, K. Schulz, and F. Bry. Towards aggregated answers for semistructured data. In International Conference on Database Theory, 2001.

....Regular path expressions have not been considered here. In addition, semistructured data are formalized as graphs, a structure more general than trees, which are the basis of our model. But regular path expressions and graph databases can be integrated into variants of our formalism (cf. MSB00] Recently, various visual query languages for semistructured data and structured document retrieval have been investigated. GW98] introduces a simple browsing system for semistructured data that helps the inexperienced user. In [CNS99] and [SD97] the user can formulate queries in a graphical ....

....optimal support for our formalism. Clearly, both keywords and structure of the query should be taken into account. As mentioned in the introduction, Complete answer aggregates have been proposed for structured document retrieval in [Meu98] and in the PhD thesis [Meu00] of the rst author. In [MSB00] we studied aggregation of answers for a hierarchy of thirteen query evaluation problems. We consider queries that have the form of sequences, trees, DAGs, or directed graphs. Queries are evaluated in databases where entries have the form of sequences, trees, DAGs, or directed graphs. ....

[Article contains additional citation context not shown here]

Holger Meuss, Klaus U. Schulz, and Francois Bry. Towards aggregated answers for semistructured data. Technical report, Institute for Computer Science, University of Munich, 2000.

....for computing the CAA and analyze their complexity, for each problem of the hierarchy. Query answering using CAAs is discussed in Section 8. Section 9 discusses related work. Section 10 is a conclusion. For space reasons, no proofs are given. They are given in the full version of this paper [26]. 2 Motivating Example Consider a database D (Figure 1) on research projects o ering information on project managers, members and publications. Assume that the database is organized as a graph with labeled edges and nodes according to a model for semistructured data [9, 19, 1] Projects x and ....

....an edge constraint in Q) Although the number of answers to a query Q may be exponential, the size of a CAA is at most linear in the size of the query and quadratic in the size of the database: Theorem 1. The size of the CAA for an evaluation problem (Q; XQ ; D) is O(q n a) The full version [26] of this paper describes situations, where a better bound O(q n) can be obtained. CAAs as Semistructured data: According to De nition 6, the links of the CAA for an evaluation problem (Q; XQ ; D) are not labeled. If x f y is an f child constraint in Q, then the label f can obviously be ....

[Article contains additional citation context not shown here]

H. Meuss, K. U. Schulz, and F. Bry. Towards aggregated answers for semistructured data. Technical report, Institute for Computer Science, University of Munich, 2000. http://www.cis.uni-muenchen.de/~meuss/agg_answers_full.ps.gz.

....structural kinds are described and their complexity is analyzed using the query hierarchy. Query answering using CAAs is discussed in Section 8. Section 9 discusses related work. Section 10 is a conclusion. For space reasons, no proofs are given. They are given in the full version of this paper [32]. 2 Motivating Example Consider a database on research projects o ering information on project managers, members and publications. Assume that the database is orga1 nized as a graph with labeled edges and nodes according to a model for semistructured data [7, 16, 26, 6] Projects x and their ....

....CAA of a simple sequence query is rst given. Then, its adaptation to simple tree queries is outlined. For space reasons, further adaptations, e.g. to tree queries involving regular path expressions, are not explained in this paper. A polynomial algorithm for this case is given in the full version [32]. Simple sequence queries The algorithm of Fig. 2 takes a simple sequence query Q and a database D as arguments and computes the CAA (DomQ ; Q ) for the evalation problem induced by Q and D. Starting from an empty array (line 3) and an empty set of edges (line 4) the algorithm adds target ....

[Article contains additional citation context not shown here]

H. Meuss et al. Towards aggregated answers for semistructured data. Tech. rep., CIS and Institute for Computer Science, University of Munich, ftp://ftp.cis.uni-muenchen.de/pub/meuss/ agg answers full.ps.gz, 2000.

No context found.

H. Meuss, K. U. Schulz, and F. Bry. "Towards Aggregated Answers for Semistructured Data". In Proc. ICDT'01, pages 346--360, 2001.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC