Database Concepts

Abstract

Very early attempts to build GIS began from scratch, using limited tools like operating systems & compiler. More recently, GIS have been built around existing database management systems (DBMS). Purchase or lease of the DBMS is a major part of the system's software cost. The DBMS handles many functions which would otherwise have to be programmed into the GIS. Any DBMS makes assumptions about the data which it handles. To make effective use of a DBMS it is necessary to fit those assumptions. Certain types of DBMS are more suitable for GIS than others because their assumptions fit spatial data better.