Reverse data exchange: Coping with nulls
Ronald Fagin, Phokion G. Kolaitis, et al.
SIGMOD/PODS/ 2009
A new type of dependency, which includes the well-known functional dependencies as a special case, is defined for relational databases. By using this concept, a new (“fourth”) normal form for relation schemata is defined. This fourth normal form is strictly stronger than Codd's “improved third normal form” (or “Boyce-Codd normal form”). It is shown that every relation schema can be decomposed into a family of relation schemata in fourth normal form without loss of information (that is, the original relation can be obtained from the new relations by taking joins). © 1977, ACM. All rights reserved. © 1977, ACM. All rights reserved.
Ronald Fagin, Phokion G. Kolaitis, et al.
SIGMOD/PODS/ 2009
Ronald Fagin, Jonathan Lenchner, et al.
MFCS 2022
Moses Charikar, Ronald Fagin, et al.
Journal of Computer and System Sciences
Alexandr Andoni, Ronald Fagin, et al.
SIGMOD 2008