PROCEEDINGS IPMU '08
Defaults in Open World Relational Databases
Navin Viswanath, Rajshekhar Sunderraman.
The Open World Assumption (OWA) has been found to
be necessary in a number of applications.
In this paper, we study
the issue of incompleteness in an
open world database. We define an
extension of the relational model
which has two forms of negation
- the explicit negation, in which
certain atoms are known to be false,
and a default negation which is a
form of non-monotonic negation for
unknown atoms in the relation. We
define operators for this extended
relational model. We show that
this model is a generalization of the
relational model in the sense that
we obtain some intuitive answers in
the negative component in addition
to the answers obtained in the
relational model.
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