Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# ST\$1Z
<a name="ST_Z-function"></a>

ST\$1Z returns the `z` coordinate of an input point. 

## Syntax
<a name="ST_Z-function-syntax"></a>

```
ST_Z(point)
```

## Arguments
<a name="ST_Z-function-arguments"></a>

 *point*   
A `POINT` value of data type `GEOMETRY`. 

## Return type
<a name="ST_Z-function-return"></a>

`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
<a name="ST_Z-function-examples"></a>

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
```