> > > What use is there for fuzzy predicates? I think it would mainly be to > stop more students from coming up with new implementations of the same > thing over and over. >
Well, I'm sorry if anyone of us who is involved on these projects have already explain the true usefulness of sqlf and fuzzy database, I guess we focus just in the technical problem, but never explain the theory. For example here is a paragraph from Flexible queries in relational databases paper: "This paper deals with this second type of "uncertainty" and is concerned essentially with database language extensions in order to deal with more expressive requirements. Indeed, consider a query such that, for instance, "retrieve the apartments which are not too expensive and not too far from downtown". In such a case, there does not exist a definite threshold for which the price becomes suddenly too high, but rather we have to discriminate between prices which are perfectly acceptable for the user, and other prices, somewhat higher, which are still more or less acceptable (especially if the apartment is close to downtown). Note that the meaning of vague predicate expressions like "not too expensive" is context/user dependent, rather than universal. Fuzzy set membership functions [26] are convenient tools for modelling user's preference profiles and the large panoply of fuzzy set connectives can capture the different user attitudes concerning the way the different criteria present in his/her query compensate or not; see [4] for a unified presentation in the fuzzy set framework of the existing proposals for handling flexible queries. Moreover in a given query, some part of the request may be less important to fulfill (e.g., in the above example, the price requirement may be judged more important than the distance to downtown); the handling of importance leads to the need for weighted connectives, as it will be seen in the following." I really think this could be something useful, but it is sometimes difficult to implement and I'm trying to make a different and easy way to do things. regards