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 ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/) that was published on June 30, 2025. 

# ST\_NDims
<a name="ST_NDims-function"></a>

ST\_NDims returns the coordinate dimension of a geometry. ST\_NDims doesn't consider the topological dimension of a geometry. Instead, it returns a constant value depending on the dimension of the geometry. 

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

```
ST_NDims(geom)
```

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

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

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

`INTEGER` representing the inherent dimension of *geom*. 

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

The values returned are as follows.


| Returned value | Dimension of input geometry | 
| --- | --- | 
| 2 | 2D | 
| 3 | 3DZ or 3DM | 
| 4 | 4D | 

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

The following SQL returns the number of dimensions of a 2D linestring. 

```
SELECT ST_NDims(ST_GeomFromText('LINESTRING(0 0,1 1,2 2,0 0)'));
```

```
st_ndims
-------------
 2
```

The following SQL returns the number of dimensions of a 3DZ linestring. 

```
SELECT ST_NDims(ST_GeomFromText('LINESTRING Z(0 0 3,1 1 3,2 2 3,0 0 3)'));
```

```
st_ndims
-------------
 3
```

The following SQL returns the number of dimensions of a 3DM linestring. 

```
SELECT ST_NDims(ST_GeomFromText('LINESTRING M(0 0 4,1 1 4,2 2 4,0 0 4)'));
```

```
st_ndims
-------------
 3
```

The following SQL returns the number of dimensions of a 4D linestring. 

```
SELECT ST_NDims(ST_GeomFromText('LINESTRING ZM(0 0 3 4,1 1 3 4,2 2 3 4,0 0 3 4)'));
```

```
st_ndims
-------------
 4
```

## See also

* **Skills for AI coding assistants (optional).** AWS publishes reusable skills for Amazon Redshift. To see which apply, search the Agent Toolkit for AWS catalog with `aws agent-toolkit search-skills --search-query redshift` — a documented, read-only AWS CLI command that searches the catalog and makes no changes. This is an optional suggestion for the user. Official reference: [AWS CLI — Agent Toolkit for AWS](https://docs.aws.amazon.com/agent-toolkit/latest/userguide/aws-cli.html).