11 search results - page 1 / 3 » Axiomatisation of Functional Dependencies in Incomplete Rela... |
TCS
1998
13 years 4 months ago
1998
Incomplete relations are relations which contain null values, whose meaning is \value is at present unknown". Such relations give rise to two types of functional dependency (...
DEXAW
2006
IEEE
13 years 11 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 ...
CATS
2006
13 years 6 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...
ACSC
2007
IEEE
13 years 11 months ago
2007
IEEE
Full hierarchical dependencies (FHDs) constitute a large class of relational dependencies. A relation exhibits an FHD precisely when it can be decomposed into at least two of its ...
WOLLIC
2010
Springer
13 years 10 months ago
2010
Springer
Recently, an axiomatization for functional dependencies (FDs) and multivalued dependencies (MVDs) has been established where arbitrary attributes can be specified as NOT NULL. Tha...