On representing indefinite and maybe information in relational databases
K.-C. Liu, Rajshekhar Sunderraman · 2003
An extension is presented of the relational model to present indefinite and maybe kinds of incomplete information. A data structure, called an I-table, is introduced, which is capable of representing indefinite and maybe facts. The information content of the I-table is defined and an operator to remove redundant facts is presented. The relational algebra is then extended, in a semantically correct way, to operate on I-tables. Queries are posed in the same way as in conventional relational algebra, but the user may expect indefinite as well as maybe answers.>