New metaphors for a visual query language

Metaphors have been proved useful in facilitating learning and using an operating system or various other tools. The paper shows, through the VISTA(^*) query language, the benefits of using metaphors in the field of database querying by end users. Within VISTA, metaphors help in visualizing concepts of the object-oriented semantic data model and in facilitating the expression of operations known to be difficult. The user is placed in a room and querying consists of direct and natural manipulations on objects of this room. Moreover, VISTA brings an answer to problems such as set comparison and combination, explicit joins, universal quantification, and graphic congestion. Another benefit of this work lies in the implementation of the user interface in an industrial setting