Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, see the blog post that was published on June 30, 2025.

ST_ZMin

ST_ZMin returns the minimum z coordinate of an input geometry.

Syntax

ST_ZMin(geom)

Arguments

Return type

DOUBLE PRECISION value of the minimum z coordinate.

If geom is empty, then null is returned.

If geom is null, then null is returned.

If geom is a 2D or 3DM geometry, then null is returned.

Examples

The following SQL returns the smallest z coordinate of a linestring in a 3DZ geometry.

SELECT ST_ZMin(ST_GeomFromEWKT('LINESTRING Z (0 1 2, 3 4 5, 6 7 8)'));

st_zmin
-----------
  2               

The following SQL returns the smallest z coordinate of a linestring in a 4D geometry.

SELECT ST_ZMin(ST_GeomFromEWKT('LINESTRING ZM (0 1 2 3, 4 5 6 7, 8 9 10 11)'));

st_zmin
-----------
  2