Handling imperfection in databases: A modal logic approach

Abstract

An extended relational data model that can deal with various kinds of imperfect information is shown under a modal logic approach. This gives a new direction to deal with imperfect information. In our extension various kinds of imperfect information can be handled simultaneously, although an extended relational model has been related with one kind of imperfect information so far. This is because our extended data model has a uniform expression and the same operations to various kinds of imperfect information. Moreover our model can support flexible queries as well as conventional queries. Thus, our approach gives an important basis to integrate different kinds of databases handling different sorts of imperfect information.