Database integrity has two complementary components: validity, which guarantees that all false information is excluded from the database, and completeness, which guarantees that all true information is included in the database. This article describes a uniform model of integrity for relational databases, that considers both validity and completeness. To a large degree, this model subsumes the prevailing model of integrity (i.e., integrity constraints). One of the features of the new model is the determination of the integrity of answers issued by the database system in response to user queries. To users, answers that are accompanied with such detailed certifications of their integrity are more meaningful. First, the model is defined and discussed. Then, a specific mechanism is described that implements this model. With this mechanism, the determination of the integrity of an answer is a process analogous to the determination of the answer itself.
[1]
Abraham Silberschatz,et al.
Database System Concepts
,
1980
.
[2]
Moshé M. Zloof.
Query-by-Example: A Data Base Language
,
1977,
IBM Syst. J..
[3]
J. D. Uiiman,et al.
Principles of Database Systems
,
2004,
PODS 2004.
[4]
David Maier,et al.
The Theory of Relational Databases
,
1983
.
[5]
Hector J. Levesque,et al.
The Logic of Incomplete Knowledge Bases
,
1982,
On Conceptual Modelling.
[6]
Amihai Motro.
SEAVE: a mechanism for verifying user presuppositions in query systems
,
1986,
TOIS.
[7]
Amihai Motro,et al.
Completeness Information and Its Application to Query Processing
,
1986,
VLDB.
[8]
C. J. Date.
An Introduction to Database Systems, Volume I, 5th Edition
,
1986
.
[9]
Raymond Reiter.
On Closed World Data Bases
,
1977,
Logic and Data Bases.