CAS
2005
14 years 10 days ago
2005
In this paper, we present a new method to estimate null values in relational database systems based on genetic algorithms. It can tune the membership functions of the linguistic v...
CATS
2006
14 years 1 months ago
2006
The implication of multivalued dependencies (MVDs) in relational databases has originally been defined in the context of some fixed finite universe (Fagin 1977, Zaniolo 1976). Whi...
EDBTW
2006
Springer
14 years 4 months ago
2006
Springer
For several reasons a database may not satisfy a given set of integrity constraints (ICs), but most likely most of the information in it is still consistent with those ICs; and cou...
DEXAW
2006
IEEE
14 years 6 months ago
2006
IEEE
We study inference rules for multivalued dependencies in relational databases with null values (NMVDs). The definition of NMVDs is dependent on the underlying relation schema and ...
ICDT
2007
ACM
14 years 6 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...