One of the problems facing NASA today is to provide scientists efficient access to a large number of distributed databases. A pointer-based, incremental database access method, Viewcache, provides such an interface for accessing distributed data sets and directories.Phase I proved the suitability of Viewcache by means of a demonstration employing three astrophysics databases (IRAS, IUE, and Einstein) and a master directory. The compactness of the pointer structures formed during database browsing and the incremental access method allows searching and inter-database cross-referencing with no actual data movement between database sites. Once the search is complete, the set of collected pointers indicating the desired data is cached. Extending Viewcache to include spatial access methods for accessing image data sets was shown to be very useful. It eased query formulations by referring directly to the image and provided efficient search for objects contained within a two-dimensional window.Potential Commercial Application: Viewcache will be a stand-alone software product running on personal computers, work stations, and mainframes. It will provide an inexpensive access to heterogeneous and distributed databases.STATUS: Project Proceded to Phase II
