Query pairs as hypertext links

A new idea is proposed for constructing object-oriented hypertext database systems: query pairs as hypertext links, where each query is defined over a collection of document objects that are classified using a class hierarchy. With this idea, users need not modify their hypertext links against the insertions, deletions and updates of document objects. Also, when a database schema (here, a class hierarchy) evolves, a systematic method can be considered to modify user-defined query-pair links. The TextLink-III system that was developed based on this idea and that is currently running is described. The notable features of TextLink-III are the following: document objects are classified by class hierarchy and the notion of class expression is used for formulating a query for a class hierarchy; multiple viewpoint support; and less link maintenance against data updates