A Note on Lossless database Decompositions.
Abstract
It is known that under a wide variety of assumptions a database decomposition is lossless if and only if the database scheme has a lossless join. Biskup, Dayal, and Bernstein have shown that when the given dependencies are functional then the database scheme has a lossless join if and only if one of the relation scheme is a key for the universal scheme. In this note the investigators supply an alternative proof of that characterization. The proof uses tools from the theory of embedded join dependencies and the theory of tuple and equality generating dependencies, but is, nevertheless, much simpler than the previously published proof. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 21, 1983
- Accession Number
- ADA141488
Entities
People
- M. Y. Vardi
Organizations
- Stanford University