• ST_Curve type
• ST_GeomCollection type
• ST_Point type
• ST_Surface type

The ST_Geometry type is the maximal supertype of the geometry type hierarchy. The ST_Geometry type supports methods that can be applied to any spatial value. The ST_Geometry type cannot be instantiated; instead, a subtype should be instantiated. When working with original formats (WKT or WKB), you can use methods such as ST_GeomFromText/ST_GeomFromWKB to instantiate the appropriate concrete type representing the value in the original format.

All of the values in an ST_Geometry value are in the same spatial reference system. The ST_SRID method can be used to retrieve or change the spatial reference system associated with the value.

Columns of type ST_Geometry or any of its subtypes cannot be included in a primary key, unique index, or unique constraint.