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\$1IsSimple
<a name="ST_IsSimple-function"></a>

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

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

```
ST_IsSimple(geom)
```

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

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

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

`BOOLEAN`

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

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

The following SQL checks if the specified linestring is simple. In this example, it isn't simple because it has self-intersection. 

```
SELECT ST_IsSimple(ST_GeomFromText('LINESTRING(0 0,10 0,5 5,5 -5)'));
```

```
 st_issimple
-----------
 false
```