An APL environment for testing relational operators and search algorithms

Abstract

A description of an APL implementation of the relational operations of Join, division, union, intersection, difference and projection is given. A number of functions are also described which are combined to provide an environment for testing search algorithms on a relational data base. These include functions to express a query as a normalized expression in the relational calculus, the conversion of this expression to a set of retrieval tables and the construction of the response relation. The relational database consists of a number of relations stored as CMS files in a virtual machine environment. The database operations use the external file handling capabilities of an APL system under VM.