A generalized relational model for indefinite and maybe information

Author

Liu, Ken-Chih ; Sunderraman, Rajshekhar

Author_Institution

AT&T Bell Lab., Naperville, IL, USA

Volume

3

Issue

1

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

65

Lastpage

77

Abstract

A generalized relational model which is capable of representing and manipulating disjunctive and maybe kinds of information is presented. A data structure, called M-table, is defined, and the information contained in the M-table is precisely stated. Redundant information in M-tables is characterized, and an operator to remove this redundant information is presented. The relational algebra is suitably generalized to deal with M-tables. Additional operators, R-projection and merge, are presented. Queries can be expressed as a combination of the various generalized relational algebraic operators. The M-table accurately models the two bounds on the external interpretation of a query. The sure component of an M-table corresponds to one of the bounds which is the set of objects which belong to the external interpretation of the query. The maybe component of an M-table corresponds to the other bound which is the set of objects for which the possibility of belonging to the external interpretation of the query cannot be ruled out

Keywords

data structures; relational databases; M-table; R-projection; data structure; generalized relational model; indefinite information; maybe information; merge; Algebra; Computer science; Data structures; Indexes; Relational databases;

fLanguage

English

Journal_Title

Knowledge and Data Engineering, IEEE Transactions on

Publisher

ieee

ISSN

1041-4347

Type

jour

DOI

10.1109/69.75890

Filename

75890