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Amazon Redshift will no longer support the creation of new Python UDFs starting November 1, 2025. If you would like to use Python UDFs, create the UDFs prior to that date. Existing Python UDFs will continue to function as normal. For more information, see the blog post .

ST_Z

ST_Z returns the z coordinate of an input point.

Syntax

ST_Z(point)

Arguments

Return type

DOUBLE PRECISION value of the m coordinate.

If point is null, then null is returned.

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

If point is the empty point, then null is returned.

If point is not a POINT, then an error is returned.

Examples

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

SELECT ST_Z(ST_GeomFromEWKT('POINT Z (1 2 3)'));

st_z
-----------
 3                

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

SELECT ST_Z(ST_GeomFromEWKT('POINT ZM (1 2 3 4)'));

st_z
-----------
 3