Soft Querying of Standard and Uncertain Databases

We provide a framework for querying of databases. We model a query as a collection of required conditions and an imperative for combining an object´s satisfaction to the individual conditions to get its overall satisfaction. We investigate tools that can enrich this process by enabling the inclusion of more human focused considerations. We discuss how to include flexible conditions with the use of fuzzy sets. We describe some more sophisticated techniques for aggregating the satisfactions of the individual conditions based on the inclusion of importances and the use of the OWA operator. We introduce a new method for aggregating the individual satisfactions that can model a lexicographic relation between the individual requirements. In addition to considering more human focused aspects of the query we look at databases in which the information in the database can have some probabilistic or possibilistic uncertainty.