126 search results - page 5 / 26 » The Complexity of Acyclic Conjunctive Queries |
PODS
2006
ACM
14 years 7 months ago
2006
ACM
Query containment is a fundamental algorithmic problem in database query processing and optimization. Under set semantics, the query-containment problem for conjunctive queries ha...
DBPL
2007
Springer
14 years 1 months ago
2007
Springer
Abstract. The complexity of containment and satisfiability of conjunctive queries over finite, unranked, labeled trees is studied with respect to the axes Child, NextSibling, the...
DILS
2006
Springer
13 years 11 months ago
2006
Springer
The Open Biomedical Ontologies (OBO) is a consortium that serves as a repository of ontologies that are structured like directed acyclic graphs. In this paper we present a language...
ICDT
2009
ACM
14 years 8 months ago
2009
ACM
We study containment and equivalence of (unions of) conjunctive queries on relations annotated with elements of a commutative semiring. Such relations and the semantics of positiv...
AMW
2011
12 years 11 months ago
2011
Abstract. We consider the problem of checking equivalence of conjunctive queries with inequalities under bag (multiset) semantics. The problem is known to be decidable in pspace an...