On Complementary and Independent Mappings on Databases.
Abstract
This document defines the notion of independent views to indicate whether the range values of the two views may be achieved independently. The concepts of complementary views indicates when the domain element can be uniquely determined by the range values of the two complementary views. The relationship between independent and complementary views is considered. In unrestricted domains, a view (but not the identify or empty view) can have more than one complementary, independent view. Databases, however, are more restricted domains: They are finite power sets. A view is monotonic if it preserves inclusion. However, in finite power sets when all views are monotonic, if a given view has another view which is independent and complementary, then this view is unique.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1984
- Accession Number
- ADA145557
Entities
People
- A. M. Keller
- J. D. Ullman
Organizations
- Stanford University