AQL: A relational data base management system and its geographical applications

Abstract

AQL (acronym for: A Query Language) is a Data Base management system based on n-ary relational model. It has been designed to help the nonspecialist in data processing in solving interactively unstructured problems, in building applications, in running simulations. A rich pattern of default options, synonyms, attribute definitions, inference and a menu facility provide an easy-to-use interface which combines data extraction facility and computational capabilities of the host programming language (i.e. APL). The extension of such a system to cover the geographic data requires extensions in both the conceptual schema and the language to represent and express concepts pertaining to the geographic nature of data. Also, definition mechanism are found to be extremely useful to represent aggregate concepts in geographic data processing. The general characteristics of AQL are widely discussed in (ANT78): here they will be reviewed briefly, then the geographic extension will be discussed.