16 search results - page 1 / 4 » Weighted Hypertree Decompositions and Optimal Query Plans |
PODS
2004
ACM
14 years 4 months ago
2004
ACM
PODS
2007
ACM
14 years 4 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...
CONSTRAINTS
2011
12 years 8 months ago
2011
Abstract. We consider the problem of decomposing an integer matrix into a positively weighted sum of binary matrices that have the consecutive-ones property. This problem is well-k...
EDBT
2006
ACM
14 years 4 months ago
2006
ACM
In this paper we present a novel approach for estimating the selectivity of XML twig queries. Such a technique is useful for approximate query answering as well as for determining...
EDBT
2012
ACM
11 years 7 months ago
2012
ACM
Query optimization in RDF Stores is a challenging problem as SPARQL queries typically contain many more joins than equivalent relational plans, and hence lead to a large join orde...