Various Representations of Geometric Objects in Spatial Relational and Spatial Object-Relational Databases Management Systems

In this paper we look at various kinds of representations of geometric objects in spatial relational (or object-relational) database management systems. We confront it with Simple Feature Access and SQL/MM (Part: 3) standards. We also try to fnd out some other representations of geometric objects that are used not only in traditional spatial database management systems but also in some NoSQL databases. We indicate functions and methods related to geometry representations such as WKT, WKB, GML, GeoJSON, GeoHash, KML, EWKT, EWKB, TWKB, HEXEWKB used in MySQL, Oracle XE and PostGIS/PostgreSQL. We illustrate this with examples, also showing some ideas for importing/exporting geometries between these database management systems.