A first approach to possibilistic queries addressed to possibilistic databases

摘要

It is now recognized that querying databases containing imprecise information raises several problems, including that of complexity. In this paper, we consider a new kind of queries, called possibilistic queries, of the form 'to what extent is it possible that a given tuple t belongs to the answer of Q (a regular relational query)". This paper is a first attempt to show that a reasonable complexity can be expected for a specified subset of possibilistic queries.