On the coNP hardness of computing certain answers over locally specified incomplete DOM-trees

Authors:
Shun'ichi Amano
Affiliations:
University of Edinburgh, School of Informatics, 5.06 Informatics Forum, 10 Crichton Street, EH8 9AB, Edinburgh, United Kingdom
Venue:
Information Processing Letters
Year:
2010

Citing 3
Cited 0

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Abstract

We consider answering queries over incomplete XML trees. Barcelo et al. identified a class of shallow queries for which the problem is efficiently solvable with node ids on trees while it is coNP-complete without them. We show that their result is essentially tight. In other words, we provide a slightly extended class of queries where node ids help no more.