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\$1IsValid
<a name="ST_IsValid-function"></a>

ST\$1IsValid returns true if the 2D projection of the input geometry is valid. For more information about the definition of a valid geometry, see [Geometric validity](spatial-terminology.md#spatial-terminology-validity). 

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

```
ST_IsValid(geom)
```

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

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

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

`BOOLEAN`

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

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

The following SQL checks if the specified polygon is valid. In this example, the polygon is invalid because the interior of the polygon isn't simply connected. 

```
SELECT ST_IsValid(ST_GeomFromText('POLYGON((0 0,10 0,10 10,0 10,0 0),(5 0,10 5,5 10,0 5,5 0))'));
```

```
 st_isvalid
-----------
 false
```