GeoServer supports several optional formats beyond the built-in data sources. In the remaining part of this chapter, we will explore a quite popular RDBMS that supports spatial data--Oracle.
Oracle is probably the most widely used commercial RDBMS. It has support for spatial data since release 7, back in the 1980s. The current release, 12, comes with two flavors of spatial data extensions--Oracle Spatial and Oracle Locator. They share the same geometry type and a basic set of operators and functions. Oracle Spatial incorporates a richer set of functions for spatial analysis. Oracle is not free open source software, such as GeoServer or PostGIS, and it has a quite complicated and expensive license model. We will not cover installation here; as long as you are using Oracle, you should have the expertise and/or a proper budget to have it up and running.