121 search results - page 2 / 25 » On Containment of Conjunctive Queries with Negation |
PODS
1998
ACM
13 years 9 months ago
1998
ACM
ICDT
2007
ACM
13 years 11 months ago
2007
ACM
Abstract. We study containment of conjunctive queries that are evaluated over databases that may contain tuples with null values. We assume the semantics of SQL for single block qu...
SEBD
2007
13 years 6 months ago
2007
We consider the problem of query containment over an object data model derived from F-logic. F-logic has generated considerable interest commercially, in the academia, and within ...
PODS
2006
ACM
14 years 5 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...
ICDT
2009
ACM
14 years 6 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...