ST_ZMax

Introduction: Returns Z maxima of the given geometry or null if there is no Z coordinate.

Format: ST_ZMax(geom: geometry)

SQL example:

SELECT ST_ZMax(ST_GeomFromText('POLYGON((0 0 1, 1 1 1, 1 2 1, 1 1 1, 0 0 1))'))

Output: 1.0