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\$1MMax
<a name="ST_MMax-function"></a>

ST\$1MMax returns the maximum `m` coordinate of an input geometry. 

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

```
ST_MMax(geom)
```

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

 *geom*   
A value of data type `GEOMETRY` or an expression that evaluates to a `GEOMETRY` type. 

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

`DOUBLE PRECISION` value of the maximum `m` coordinate.

If *geom* is empty, then null is returned. 

If *geom* is null, then null is returned. 

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

## Examples
<a name="ST_MMax-function-examples"></a>

The following SQL returns the largest `m` coordinate of a linestring in a 3DM geometry. 

```
SELECT ST_MMax(ST_GeomFromEWKT('LINESTRING M (0 1 2, 3 4 5, 6 7 8)'));
```

```
st_mmax
-----------
  8
```

The following SQL returns the largest `m` coordinate of a linestring in a 4D geometry. 

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

```
st_mmax
-----------
  11
```