+612 9045 4394
The Nested Universal Relation Database Model : Lecture Notes in Computer Science - Mark Levene

The Nested Universal Relation Database Model

Lecture Notes in Computer Science

Paperback Published: 1st June 1992
ISBN: 9783540554936
Number Of Pages: 177

Share This Book:


or 4 easy payments of $31.26 with Learn more
Ships in 5 to 9 business days

This monograph describes a method of data modelling whosebasic aim is to make databases easier to use by providingthem with logical data independence. To achieve this, thenested UR (universal relation) model is defined by extendingthe classical UR model to nested relations. Nested relationsgeneralize flat relations and allow hierarchicallystructured objects to be modelled directly, whereas theclassical UR model allows the user to view the database asif it were composed of a single flat relation. The authorpresents a comprehensive formalisation of the nestedrelational model, which incorporated null values into themodel. Functional data dependencies and the classical notionof lossless decomposition are extended to nested relationsand an extended chase procedure is defined to test thesatisfaction of the data dependencies. The nested UR modelis defined, and the classical UR model is shown to be aspecial case of the nested model.This implies that an URinterface canbe implemented by using the nested UR model,thus gaining the full advantages of nested relations overflat relations.

The underlying database models.- The null extended nested relational model.- Null extended data dependencies and the extended chase.- A universal relation model for a nested database.- A universal relation model for a single nested relation.- Concluding remarks and ongoing research.

ISBN: 9783540554936
ISBN-10: 3540554939
Series: Lecture Notes in Computer Science
Audience: General
Format: Paperback
Language: English
Number Of Pages: 177
Published: 1st June 1992
Publisher: Springer-Verlag Berlin and Heidelberg Gmbh & Co. Kg
Country of Publication: DE
Dimensions (cm): 23.11 x 15.49  x 1.02
Weight (kg): 0.3