Mixing Selections and Foreign Key Joins in Queries against Possibilistic Databases

• Authors: Patrick Bosc;Olivier Pivert
• Venue: ISMIS '02 Proceedings of the 13th International Symposium on Foundations of Intelligent Systems
• Year: 2002

This paper deals with the querying of databases containing ill-known attribute values represented by possibility distributions. It investigates a query language with two operators: selection and a foreign key join operator which allows to express queries involving several relations at a time. The key idea is to impose a strong connection between the relations resulting from the operators and their interpretation in terms of more or less possible worlds. From a computational point of view, an interesting property of the queries considered is that they can be evaluated in a "compact" way, i.e., they do not require explicit handling of the possible worlds attached to the possibilistic database.