On Some Extension of the Query Language for Incomplete Information Systems

Article type: Research Article

Authors: Imieliński, Tomasz

Affiliations: Institute of Computer Science, Polish Academy of Sciences

Abstract: In the paper properties of en extension of a query language for incomplete information systems by a new descriptor “known(i)” are examined. Introducing a new descriptor “known(i)” allows to distinguish the objects about which our knowledge is complete, and increases the descriptive power of the language. It is shown that every query (term) is equivalent to a term in a simpler canonical form. Completeness results are presented.

Keywords: query languages, incomplete information, data bases

DOI: 10.3233/FI-1982-53-407

Journal: Fundamenta Informaticae, vol. 5, no. 3-4, pp. 319-342, 1982