GeoSPARQL Functions

SC13-03 (v0.86.0): this page documents the implementation status of all GeoSPARQL 1.1 functions in pg_ripple.

pg_ripple implements the GeoSPARQL 1.1 extension (OGC, 2022) via the PostGIS integration layer. Geometry literals are stored as WKT strings with the geo:wktLiteral datatype.

Topological Relations

GeoSPARQL topological relation functions operate on geometry literals and return xsd:boolean.

Function	Prefix	Status	Notes
`geo:sfEquals`	geo:	✅ Implemented	PostGIS `ST_Equals`
`geo:sfDisjoint`	geo:	✅ Implemented	PostGIS `ST_Disjoint`
`geo:sfIntersects`	geo:	✅ Implemented	PostGIS `ST_Intersects`
`geo:sfTouches`	geo:	✅ Implemented	PostGIS `ST_Touches`
`geo:sfCrosses`	geo:	✅ Implemented	PostGIS `ST_Crosses`
`geo:sfWithin`	geo:	✅ Implemented	PostGIS `ST_Within`
`geo:sfContains`	geo:	✅ Implemented	PostGIS `ST_Contains`
`geo:sfOverlaps`	geo:	✅ Implemented	PostGIS `ST_Overlaps`
`geo:ehEquals`	geo:	✅ Implemented	Egenhofer equals
`geo:ehDisjoint`	geo:	✅ Implemented	Egenhofer disjoint
`geo:ehMeet`	geo:	✅ Implemented	Egenhofer meet
`geo:ehOverlap`	geo:	✅ Implemented	Egenhofer overlap
`geo:ehCovers`	geo:	✅ Implemented	Egenhofer covers
`geo:ehCoveredBy`	geo:	✅ Implemented	Egenhofer covered by
`geo:ehInside`	geo:	✅ Implemented	Egenhofer inside
`geo:ehContains`	geo:	✅ Implemented	Egenhofer contains
`geo:rcc8dc`	geo:	✅ Implemented	RCC8 DC
`geo:rcc8ec`	geo:	✅ Implemented	RCC8 EC
`geo:rcc8po`	geo:	✅ Implemented	RCC8 PO
`geo:rcc8tppi`	geo:	✅ Implemented	RCC8 TPPi
`geo:rcc8tpp`	geo:	✅ Implemented	RCC8 TPP
`geo:rcc8ntppi`	geo:	✅ Implemented	RCC8 NTPPi
`geo:rcc8ntpp`	geo:	✅ Implemented	RCC8 NTPP
`geo:rcc8eq`	geo:	✅ Implemented	RCC8 EQ

Non-topological Functions

Function	Status	Returns	Notes
`geo:distance`	✅ Implemented	`xsd:double`	PostGIS `ST_Distance`; unit = degrees (EPSG:4326)
`geo:buffer`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Buffer`
`geo:convexHull`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_ConvexHull`
`geo:intersection`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Intersection`
`geo:union`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Union`
`geo:difference`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Difference`
`geo:symDifference`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_SymDifference`
`geo:envelope`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Envelope`
`geo:boundary`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_Boundary`
`geo:area`	✅ Implemented	`xsd:double`	PostGIS `ST_Area`; unit = square degrees
`geo:length`	✅ Implemented	`xsd:double`	PostGIS `ST_Length`
`geo:asWKT`	✅ Implemented	`geo:wktLiteral`	PostGIS `ST_AsText`
`geo:asGeoJSON`	✅ Implemented	`xsd:string`	PostGIS `ST_AsGeoJSON`

Known Gaps

Function	Status	Reason
`geo:metricArea`	⏳ Planned	Requires CRS-aware unit conversion via `GEOGRAPHY` type
`geo:metricLength`	⏳ Planned	Requires CRS-aware unit conversion
`geo:metricPerimeter`	⏳ Planned	Requires CRS-aware unit conversion
`geo:metricDistance`	⏳ Planned	Requires CRS-aware unit conversion
DGGS functions	🔜 Future	Discrete Global Grid Systems (DGGS) not yet implemented

Enabling GeoSPARQL

GeoSPARQL requires the PostGIS extension:

CREATE EXTENSION postgis;
CREATE EXTENSION pg_ripple CASCADE;

See GeoSPARQL + PostGIS Integration for a full tutorial.