An almost path-free very high-level interactive data manipulation language for a microcomputer-based database system

VIADUCT is a very high-level non-procedural language designed to simplify usage of MDBS, a microcomputer database management system. Users need not have any knowledge of the structure of the database, because no path through the database is specified in a VIADUCT command. Instead, VIADUCT automatically determines which of a number of paths should be traversed in order to process the command. As this choice of path can critically affect the processing time required, VIADUCT chooses that path which is most likely to minimize the number of record occurrences retrieved from the database. But when a command can have more than one valid semantic interpretation, VIADUCT computes and then displays the alternative paths from which the user is required to make a choice. Following a brief description of relevant aspects of MDBS, an overview of VIADUCT is given. The body of the paper describes the algorithms that are used to find paths through the database, as well as the path-traversal algorithms. An evaluation of VIADUCT is presented and some restrictions noted