Flexible queries in object-oriented databases: on the study of bags

Flexible querying provides new interrogation tools that enable the user to express preferences inside requirements and priorities inside compound queries. The answers are qualified and presented as a set of discriminated elements according to their degree of adequation. The objective of our work is to define a flexible query language for an object-oriented database and to provide a general framework on which applications can fully exploit the graduality associated with their processing tools. In this paper, we focus specifically on the study of bags.