A.: Exploiting Fuzzy-SQL in Case-Based Reasoning

The use of database technologies for implementing CBR techniques i attracting a lot of attention for several reasons. First, the possibility of using standard DBMS for storing and representing cases significantly reduces the effort needed to develop a CBR system; in fact, data of interest are usually already stored into relational databases and used for differ-ent purposes as well. Finally, the use of standard query lan-guages, like SQL, may facilitate the introduction of a case-based system into the real-world, by putting retrieval on the same ground of normal database queries. Unfortunately, SQL is not able to deal with queries like those needed in a CBR system, so different approaches have been tried, in order to build retrieval engines able to exploit, at the lower level, stan-dard SQL. In this paper, we present a proposal where case retrieval is implemented byusing a fuzzy version of SQL. In the presented approach a fuzzy notion of similarity is adopted and an extended version of SQL, dealing with fuzzy predi-cates, is introduced. A case-based system prototype xploit-ing Fuzzy-SQL as a retrieval engine is then presented