Analysis of Typed Inclusion Dependences with Null Values


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

Null values have become an urgent problem since the creation of the relational data model. The impact of uncertainty affects all types of dependences used in designing and operating a database. This fully applies to inclusion dependences, which are the theoretical basis for referential integrity on the data. Attempts to solve this problem contain inaccuracies in the statement of the problem and its solution. The errors in formulation of the problem can be associated with use in the definition of untyped inclusion dependences, which leads to permutations of the attributes, although, the attributes in database technology are identified by name and not by their place. In addition, linking with the use of inclusion dependences of heterogeneous attributes, even of the same type, is a sign of lost functional dependences and leads to interaction of inclusion dependences and non-trivial functional dependences. Inaccuracies in the solution of the problem are contained in the statements of axioms and proof of their properties, including completeness. In this paper we propose an original solution of this problem only for typed inclusion dependences in the presence of Null values: a new axiom system is proposed, its completeness and soundness are proven. On the basis of inference rules, we developed an algorithm for the construction of a nonredundant set of typed inclusion dependences. The correctness of the algorithm is proven.

About the authors

V. S. Zykin

Omsk State Technical University

Author for correspondence.
Email: vszykin@mail.ru
Russian Federation, Omsk, 644050

S. V. Zykin

Sobolev Institute of Mathematics, Siberian Branch, Russian Academy of Sciences

Author for correspondence.
Email: szykin@mail.ru
Russian Federation, Novosibirsk, 630090

Supplementary files

Supplementary Files
Action
1. JATS XML

Copyright (c) 2018 Allerton Press, Inc.