Sugeno fuzzy integral as a basis for the interpretation of flexible queries involving monotonic aggregates

This paper is situated in the area of flexible queries addressed to regular relational databases. Some works have been carried out in the past years in order to design languages allowing the expression of queries involving preferences through the use of fuzzy predicates. In the relational setting, extensions of the relational algebra as well as of SQL-like languages have been proposed and a wide range of fuzzy queries has been made available. However, the use of conditions involving an aggregate function applying to a fuzzy set is not yet possible except for the cardinality (count) in the context of the so-called fuzzy quantified statements. The objective of this paper is to investigate how (and under which conditions) other aggregate functions (such as the maximum...) could be applied to fuzzy sets in a flexible query.