Paper Info
Title
On The Implication Of Multivalued Dependencies In Partial Database Relations
Abstract
The implication of multivalued dependencies (MVDs) in relational databases has originally and independently been defined in the context of some fixed finite universe by Delobel, Fagin, and Zaniolo. Biskup observed that the original axiomatisation for MVD implication does not reflect the fact that the complementation rule is merely a means to achieve database normalisation. He proposed two alternative ways to overcome this deficiency: i) an axiomatisation that does represent the role of the complementation rule adequately, and ii) a notion of MVD implication in which the underlying universe of attributes is left undetermined together with an axiomatisation of this notion.In this paper we investigate multivalued dependencies with null values (NMVDs) as defined and axiomatised by Lien. We show that Lien's axiomatisation does not adequately reflect the role of the complementation rule, and extend Biskup's findings for MVDs in total database relations to NMVDs in partial database relations. Moreover, a correspondence between (minimal) axiomatisations in fixed universes that do reflect the property of complementation and (minimal) axiomatisations in undetermined universes is shown.
Year
DOI
Venue
2008
10.1142/S0129054108005899
INTERNATIONAL JOURNAL OF FOUNDATIONS OF COMPUTER SCIENCE
Keywords
Field
DocType
multivalued dependency, null value, implication, inference, minimality
Discrete mathematics,Multivalued dependency,Lien,Relational database,Inference,MVDS,Mathematics,Database,Null (SQL)
Journal
Volume
Issue
ISSN
19
3
0129-0541
Citations 
PageRank 
References 
16
0.50
27
Authors
1
Name
Order
Citations
PageRank
Sebastian Link130719.17