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Querying Incomplete Information in Semistructured Data

✍ Scribed by Yaron Kanza; Werner Nutt; Yehoshua Sagiv

Publisher
Elsevier Science
Year
2002
Tongue
English
Weight
323 KB
Volume
64
Category
Article
ISSN
0022-0000

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✦ Synopsis

graphs, which give rise to three variants of matching. For each variant, we provide algorithms and complexity results. In the filter phase, the maximal matchings resulting from the search phase are subjected to constraints, which may be weak or strong. Strong constraints require all their variables to be bound, while weak constraints do not. We describe a polynomial algorithm for evaluating a special type of queries with filter constraints, and assess the complexity of evaluating other queries for several kinds of constraints. In the final part, we investigate the containment problem for queries consisting only of search constraints under the different semantics.

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