PostGIS is a spatial extender for PostgreSQL. It can be a good OpenGIS Simple Features for SQL-compliant spatial database because it allows you to use location SQL queries for geographic objects while remaining free and open source. Because spatial data is usually related to various types of data, PostGIS allows PostgreSQL developers to encode more complex spatial relationships. The first version (0.1) of PostGIS was released in May 2001 by Refractions Research. The latest released version of PostGIS is PostGIS 3.1.2.
When using PostGIS, we are able to execute our spatial data just like anything else in SQL statements. With the power of SQL, developers can conveniently perform spatial database transactions, backups, integrity checks, less data redundancy, multi-user operations, and security controls.
The following is a list of advantages of PostGIS:
- It offers complicated spatial tasks, spatial operators, and spatial functions.
- It significantly shortens the development time of applications.
- It allows spatial SQL querying using simple expressions for spatial relationships, such as the distance, adjacency, and containment, and for spatial operations, such as the area, length, intersection, union, and buffer.
In 2006, the Open Geospatial Consortium evaluated that "PostGIS implements the specified standard for simple features for SQL." In fact, PostGIS can be used as a backend for many software systems such as OpenStreetMap, ArcGIS, OpenJUMP, MapGuide, Kosmo, and QGIS. Furthermore, PostGIS also has an open source extension named "pgRouting" that provides geospatial routing functionality with many algorithms, including the all-pairs algorithm, Johnson’s algorithm, the Floyd-Warshall algorithm, A*, the bidirectional Dijkstra and traveling salesperson algorithms, and more.
