ViewFinder: an object browser

ViewFinder is a graphical tool for browsing in databases that provides a fl exible, yet intuitive environment for exploratory searches. The design appr oach has been to provide maximum functionality and generality without sacri ficing simplicity. The constructs of Viewfinder's external model are essent ially object-oriented: class and token objects, membership relationships be tween tokens and classes, generalization relationships between classes, inh eritance, and so on. This external model is based on an internal model whic h resembles a semantic network. Such a network may be extracted from a vari ety of data models, including object-oriented, entity-relationship and exte nded relational models. This architecture gives Viewfinder a large degree o f model independence. The main construct of the external model are displays of objects (either classes or tokens), called views. Commands are availabl e for efficient traversal of the database, displaying views of any class or token. To speed up repetitive searches, views may be synchronized: the use r sets up several views, linked in a tree-like structure, so that when the information displayed in the root view is modified (e.g. scrolled by the us er), the contents of the other views change automatically. Additional comma nds are available to search, order, aggregate and select the information di splayed in a view, thus providing a simple query facility. (C) 1999 Elsevie r Science B.V. All rights reserved.