16 search results - page 1 / 4 » Weighted Hypertree Decompositions and Optimal Query Plans |
PODS
2004
ACM
14 years 7 months ago
2004
ACM
PODS
2007
ACM
14 years 7 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 11 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 7 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 9 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...