Geospatial Support

Ontul provides PostGIS-compatible geospatial SQL functions, enabling location-based queries and spatial analysis directly within SQL.

Implementation

Geospatial functions are powered by JTS (Java Topology Suite) and registered as Calcite UDFs. The default SRID is 4326 (WGS84).

Spatial Functions

Construction

Function	Description
`ST_GeomFromText(wkt)`	Create geometry from WKT
`ST_GeomFromText(wkt, srid)`	Create geometry from WKT with SRID
`ST_Point(x, y)`	Create a point
`ST_MakePoint(x, y)`	Create a point (alias)
`ST_GeomFromGeoJSON(json)`	Create geometry from GeoJSON

Output

Function	Description
`ST_AsText(geom)`	Export to WKT
`ST_AsGeoJSON(geom)`	Export to GeoJSON

Spatial Relationships

Function	Description
`ST_Distance(g1, g2)`	Euclidean distance between geometries
`ST_Contains(g1, g2)`	Check if g1 contains g2
`ST_Within(g1, g2)`	Check if g1 is within g2
`ST_Intersects(g1, g2)`	Check if geometries intersect
`ST_Overlaps(g1, g2)`	Check if geometries overlap
`ST_Touches(g1, g2)`	Check if geometries touch

Processing

Function	Description
`ST_Area(geom)`	Polygon area
`ST_Buffer(geom, dist)`	Create buffer zone
`ST_Centroid(geom)`	Compute centroid
`ST_Union(g1, g2)`	Union of geometries
`ST_Intersection(g1, g2)`	Intersection of geometries
`ST_Envelope(geom)`	Bounding box
`ST_Length(geom)`	LineString length

Accessors

Function	Description
`ST_X(geom)` / `ST_Y(geom)`	Coordinate extraction
`ST_SRID(geom)`	Get SRID
`ST_SetSRID(geom, srid)`	Set SRID
`ST_GeometryType(geom)`	Geometry type name
`ST_NumPoints(geom)`	Vertex count
`ST_IsValid(geom)`	Validity check

Example

SELECT name, ST_Distance(
  ST_Point(126.9780, 37.5665),
  ST_GeomFromText(location)
) AS distance
FROM iceberg_catalog.geo.stores
WHERE ST_Contains(
  ST_Buffer(ST_Point(126.9780, 37.5665), 0.01),
  ST_GeomFromText(location)
)
ORDER BY distance;