PostGIS [SEP] based on
PostGIS
PostGIS ( ) is an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. PostGIS follows the Simple Features for SQL specification from the Open Geospatial Consortium (OGC).
Technically PostGIS was implemented as a "PostgreSQL external extension".
History.
Refractions Research released the first version of PostGIS in 2001 under the GNU General Public License. After six release candidates, a stable "1.0" version followed on April 19, 2005.
In 2006 the OGC registered
by GEOS).
- R-tree-over-GiST (Generalized Search Tree) spatial indexes for high speed spatial querying.
- Index selectivity support, to provide high performance query plans for mixed spatial/non-spatial queries.
- For raster data, PostGIS WKT Raster (now integrated into PostGIS 2.0+ and renamed PostGIS Raster)
The PostGIS implementation is based on "light-weight" geometries and indexes optimized to reduce disk and memory footprint. Using light-weight geometries helps servers increase the