[en] OR-sets and marked null values are two ways of representing incomplete information in relational databases. Existing relational database systems do not support OR-sets, but can be easily extended to support marked null values. We show that relations with OR-sets can be transformed into relations with marked null values without hanging the answers to conjunctive queries.
Disciplines :
Electrical & electronics engineering
Author, co-author :
Wijsen, Jef ; Université de Mons > Faculté des Sciences > Service des Systèmes d'information
Language :
English
Title :
The conjunctive information in disjunctive databases
