126 search results - page 7 / 26 » The Complexity of Acyclic Conjunctive Queries |
PODS
1998
ACM
15 years 1 months ago
1998
ACM
We study the complexity of the problem of answering queries using materialized views. This problem has attracted a lot of attention recently because of its relevance in data integ...
PODS
2006
ACM
15 years 9 months ago
2006
ACM
This is a survey of algorithms, complexity results, and general solution techniques for efficiently processing queries on tree-structured data. I focus on query languages that com...
IPL
2010
14 years 8 months ago
2010
We derive a new generalization of lowest common ancestors (LCAs) in dags, called the lowest single common ancestor (LSCA). We show how to preprocess a static dag in linear time su...
PODS
2007
ACM
15 years 9 months ago
2007
ACM
The generalized hypertree width GHW(H) of a hypergraph H is a measure of its cyclicity. Classes of conjunctive queries or constraint satisfaction problems whose associated hypergr...
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KR
2010
Springer
15 years 1 months ago
2010
Springer
The DL-Lite family of Description Logics has been designed with the specific goal of allowing for answering complex queries (in particular, conjunctive queries) over ontologies w...