Set up geospatial data with PostGIS

Confirm extension availability

PostGIS is an extension, not a built-in feature of every PostgreSQL hosting plan. Confirm that your exact database instance permits the required extension version. On a database with suitable privileges, installation commonly begins with:

CREATE EXTENSION IF NOT EXISTS postgis;

Define the coordinate system

Store geometry with a known spatial reference identifier (SRID). Longitude/latitude data typically needs explicit handling; do not treat degrees as metres.

Example table

CREATE TABLE points_of_interest (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  name text NOT NULL,
  geom geometry(Point, 4326) NOT NULL
);
CREATE INDEX poi_geom_gist ON points_of_interest USING GIST (geom);

Validate spatial queries

Use PostGIS functions appropriate to geometry or geography, check SRID conversion and examine query plans. Only add spatial indexes for observed query patterns. Test calculations with known benchmark coordinates.

Production considerations

Spatial extensions have version and migration considerations. Include extension availability in recovery plans. Consult PostGIS documentation for function semantics.