ST_ConcaveHull

Introduction: Return the Concave Hull of polygon A, with alpha set to pctConvex[0, 1] in the Delaunay Triangulation method, the concave hull will not contain a hole unless allowHoles is set to true

Format:

ST_ConcaveHull (A: Geometry, pctConvex: Double)

ST_ConcaveHull (A: Geometry, pctConvex: Double, allowHoles: Boolean)

Since: v1.4.0

Example:

SELECT ST_ConcaveHull(ST_GeomFromWKT('POLYGON((175 150, 20 40, 50 60, 125 100, 175 150))'), 1)

Output:

POLYGON ((125 100, 20 40, 50 60, 175 150, 125 100))