204 search results - page 7 / 41 » Containment of Conjunctive Queries with Negation: Algorithms... |
CIKM
2008
Springer
13 years 9 months ago
2008
Springer
Relevance feedback has been demonstrated to be an effective strategy for improving retrieval accuracy. The existing relevance feedback algorithms based on language models and vect...
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...
DBA
2006
13 years 9 months ago
2006
In order to facilitate query processing, the information contained in data warehouses is typically stored as a set of materialized views. Deciding which views to materialize prese...
VLDB
2006
ACM
14 years 8 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...
ICDE
2006
IEEE
14 years 9 months ago
2006
IEEE
We present MiniCount, the first efficient sound and complete algorithm for finding maximally contained rewritings of conjunctive queries with count, using conjunctive views with c...