126 search results - page 12 / 26 » The Complexity of Acyclic Conjunctive Queries |
ICDT
2012
ACM
12 years 8 hour ago
2012
ACM
Previous studies of incomplete XML documents have identified three main sources of incompleteness – in structural information, data values, and labeling – and addressed data ...
PODS
2007
ACM
14 years 9 months ago
2007
ACM
In [3], we introduced a framework for querying and updating probabilistic information over unordered labeled trees, the probabilistic tree model. The data model is based on trees ...
PODS
2012
ACM
12 years 1 days ago
2012
ACM
Data is increasingly being bought and sold online, and Webbased marketplace services have emerged to facilitate these activities. However, current mechanisms for pricing data are ...
WEBDB
2005
Springer
14 years 3 months ago
2005
Springer
In recent years it has been argued that when XML encodings become complex, DOM trees are no longer adequate for query processing. Alternative representations of XML documents, suc...
VLDB
2006
ACM
14 years 9 months ago
2006
ACM
In this paper we study the following problem. Given a database and a set of queries, we want to find a set of views that can compute the answers to the queries, such that the amoun...