PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRI's SDE or Oracle's Spatial extension. PostGIS follows the OpenGIS "Simple Features Specification for SQL" and has been certified as compliant with the "Types and Functions" profile. PostGIS/PostgreSQL includes the following functionality: * Simple Features as defined by the OpenGIS Consortium (OGC) * Support for Well-Known Text and Well-Known Binary representations of GIS objects * Fast spatial indexing using GiST * Geospatial analysis functions * PostgreSQL JDBC extension objects corresponding to the geometries * Support for OGC access functions as defined by the Simple Features Specification The package is postgis2 for historical reasons; this is currently PostGIS 3 and intends to track the most recent stable release.