CompoundCurve Data Type
The CompoundCurve type is a collection of geometries of types LineString and CircularString. No other types are allowed in the collection. The curve has to be continuous, which means where the former string ends, the next string must start.
Examples:
Without specifying SRID:
CREATE TABLE curves (name VARCHAR(30), curve COMPOUNDCURVE);
With specifying SRID:
CREATE TABLE curves (name VARCHAR(30), curve COMPOUNDCURVE SRID 4326);
Show an arc followed by a line closing the half circle:
CREATE TABLE curves (id INT, curve COMPOUNDCURVE);
INSERT INTO curves (id, curve) VALUES (1, GeomFromText('COMPOUNDCURVE(CIRCULARSTRING(0 0, 2 2, 4 0), (4 0, 0 0))'));