373 search results - page 2 / 75 » Querying Priced Information in Databases: The Conjunctive Ca... |
ICDT
2009
ACM
14 years 5 months ago
2009
ACM
The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...
ICDT
2009
ACM
14 years 5 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...
EDBT
2004
ACM
14 years 5 months ago
2004
ACM
We study the problem of answering queries over sources with limited access patterns. The problem is to decide whether a given query Q is feasible, i.e., equivalent to an executable...
ICDT
2007
ACM
13 years 11 months ago
2007
ACM
Query containment is a fundamental problem of databases. Given two queries q1 and q2, it asks whether the set of answers to q1 is included in the set of answers to q2 for any datab...
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 ...