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/). 

# GREATEST and LEAST functions
<a name="r_GREATEST_LEAST"></a>

Returns the largest or smallest value from a list of any number of expressions.

## Syntax
<a name="r_GREATEST_LEAST-synopsis"></a>

```
GREATEST (value [, ...])
LEAST (value [, ...])
```

## Parameters
<a name="r_GREATEST_LEAST-arguments"></a>

*expression\$1list*  
A comma-separated list of expressions, such as column names. The expressions must all be convertible to a common data type. NULL values in the list are ignored. If all of the expressions evaluate to NULL, the result is NULL.

## Returns
<a name="r_GREATEST_LEAST-returns"></a>

Returns the greatest (for GREATEST) or least (for LEAST) value from the provided list of expressions.

## Example
<a name="r_GREATEST_LEAST-examples"></a>

The following example returns the highest value alphabetically for `firstname` or `lastname`.

```
select firstname, lastname, greatest(firstname,lastname) from users
where userid < 10
order by 3;

 firstname | lastname  | greatest
-----------+-----------+-----------
 Lars      | Ratliff   | Ratliff
 Reagan    | Hodge     | Reagan
 Colton    | Roy       | Roy
 Barry     | Roy       | Roy
 Tamekah   | Juarez    | Tamekah
 Rafael    | Taylor    | Taylor
 Victor    | Hernandez | Victor
 Vladimir  | Humphrey  | Vladimir
 Mufutau   | Watkins   | Watkins
(9 rows)
```