39 search results - page 6 / 8 » Data Complexity of Answering Unions of Conjunctive Queries i... |
VLDB
2006
ACM
14 years 7 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...
ICDT
2007
ACM
14 years 1 months ago
2007
ACM
Abstract. We define and study formal privacy guarantees for information integration systems, where sources are related to a public schema by mappings given by source-to-target dep...
PODS
2004
ACM
14 years 7 months ago
2004
ACM
We study the problem of answering queries over sources with limited access patterns. Given a first-order query Q, the problem is to decide whether there is an equivalent query whi...
EDBT
2008
ACM
14 years 7 months ago
2008
ACM
In this paper we study the problem of mining all frequent queries in a given database table, a problem known to be intractable even for conjunctive queries. We restrict our attent...
PODS
2007
ACM
14 years 7 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 ...