postgis

postgis : PostGIS geometry and geography spatial types and functions

Overview

Packages

Source

Install

Make sure PGDG repo available:

pig repo add pgdg -u    # add pgdg repo and update cache

Install this extension with pig:

pig install postgis;		# install via package name, for the active PG version

pig install postgis -v 18;   # install for PG 18
pig install postgis -v 17;   # install for PG 17
pig install postgis -v 16;   # install for PG 16
pig install postgis -v 15;   # install for PG 15
pig install postgis -v 14;   # install for PG 14

Create this extension with:

CREATE EXTENSION postgis;

Usage

Source: Official manual, current manual HTML, release notes, patch release announcement

postgis adds spatial types, indexes, and SQL functions to PostgreSQL. The main user-facing split is between geometry for planar/projected work and geography for spherical calculations on longitude/latitude data.

Basic setup

CREATE EXTENSION postgis;
SELECT PostGIS_Full_Version();

Core types and functions

CREATE TABLE sensors (
  id bigserial PRIMARY KEY,
  geom geometry(Point, 4326),
  geog geography(Point, 4326)
);

SELECT ST_SetSRID(ST_MakePoint(-73.985, 40.748), 4326);
SELECT ST_Intersects(a.geom, b.geom) FROM a, b;
SELECT ST_DWithin(a.geom, b.geom, 100);
SELECT ST_Distance(a.geog, b.geog);
SELECT ST_Transform(geom, 3857) FROM sensors;

• constructors: ST_MakePoint, ST_GeomFromText, ST_GeomFromGeoJSON
• relationships: ST_Intersects, ST_Contains, ST_Within, ST_DWithin
• measurements and transforms: ST_Distance, ST_Area, ST_Length, ST_Transform
• processing: ST_Buffer, ST_Intersection, ST_Union

Spatial indexes

CREATE INDEX idx_sensors_geom ON sensors USING GIST (geom);

The official manual continues to recommend GiST as the general-purpose spatial index, with BRIN and SP-GiST available for specific data distributions and tradeoffs.

Caveats

• Use geometry in an appropriate projected SRID for planar distances and areas; use geography when you need meter-based spheroidal calculations.
• PostGIS 3.6.3 is a patch release dated 2026-04-14. The release notes describe fixes and a security hardening change, not a new stub-level usage surface, so this refresh mostly trims and aligns the stub with the current manual.