A rigorous approach to data type specification
Emmanuel J. Yannakoudakis, G P Cheng · ITNOW · 1987
Abstract One of the most important roles of a Data Definition Language (DDL) is the specification of data items or attributes. In data processing, data types are classified into a) character strings, and b) numeric. The concept of the specification of a data type is by no means triviaL In the past, a data type was loosely specified and terms such as number, numeral, etc, were confusingly used in most DDL and programming language publications, A formal approach to data type specification was adopted recently by the database committee of the Internationa] Standards Organisation (ISO). We have found that ambiguities still arise in the ISO standard. This paper presents a rigorous approach to data type specification.