# stddev_samp

> For the complete documentation index, see [llms.txt](https://docs.redpanda.com/llms.txt). Component-specific: [cloud-data-platform-full.txt](https://docs.redpanda.com/cloud-data-platform-full.txt)

---
title: stddev_samp
latest-operator-version: v26.1.4
latest-console-tag: v3.7.3
latest-connect-version: 4.93.0
latest-redpanda-tag: v26.1.9
docname: sql/sql-functions/aggregate-functions/statistics/stddev-samp
page-component-name: cloud-data-platform
page-version: master
page-component-version: master
page-component-title: Cloud
page-relative-src-path: sql/sql-functions/aggregate-functions/statistics/stddev-samp.adoc
page-edit-url: https://github.com/redpanda-data/cloud-docs/edit/main/modules/reference/pages/sql/sql-functions/aggregate-functions/statistics/stddev-samp.adoc
description: The `stddev_samp()` aggregate function calculates the sample standard deviation of a set of numeric values.
page-topic-type: reference
page-git-created-date: "2026-05-26"
page-git-modified-date: "2026-05-26"
---

<!-- Source: https://docs.redpanda.com/cloud-data-platform/reference/sql/sql-functions/aggregate-functions/statistics/stddev-samp.md -->

The `stddev_samp()` aggregate function calculates the sample standard deviation of a set of numeric values. This function measures how much the values deviate from their mean, assuming the data is a sample of a larger population.

## [](#syntax)Syntax

The syntax for this function is:

```sql
STDDEV_SAMP(expression)
```

## [](#parameters)Parameters

-   `expression`: Numeric expression or column.


## [](#examples)Examples

The following example uses a simplified version of the `film` table from the Pagila database, containing only the `title`, `length` and `rating` columns. The complete schema for the `film` table can be found on the [Pagila](https://www.postgresql.org/ftp/projects/pgFoundry/dbsamples/pagila/pagila/) database website.

```sql
DROP TABLE IF EXISTS film;
CREATE TABLE film (
  title text NOT NULL,
  length int,
  rating int
);
INSERT INTO film(title, length, rating) VALUES
  ('ATTRACTION NEWTON', 83, 5),
  ('CHRISTMAS MOONSHINE', 150, 7),
  ('DANGEROUS UPTOWN', 121, 4),
  ('KILL BROTHERHOOD', 54, 3),
  ('HALLOWEEN NUTS', 47, 5),
  ('HOURS RAGE', 122, 7),
  ('PIANIST OUTFIELD', 136, 7),
  ('PICKUP DRIVING', 77, 3),
  ('INDEPENDENCE HOTEL', 157, 7),
  ('PRIVATE DROP', 106, 4),
  ('SAINTS BRIDE', 125, 3),
  ('FOREVER CANDIDATE', 131, 7),
  ('MILLION ACE', 142, 5),
  ('SLEEPY JAPANESE', 137, 4),
  ('WRATH MILE', 176, 7),
  ('YOUTH KICK', 179, 7),
  ('CLOCKWORK PARADISE', 143, 5);
```

The following query uses the `stddev_samp()` function to calculate the sample standard deviation for the `length` column where `rating` is greater than or equal to 4:

```sql
SELECT
    STDDEV_SAMP(length) AS LengthSampleStdDev
FROM film
WHERE rating >= 4;
```

The query returns:

```sql
 lengthsamplestddev
--------------------
  34.92503746251735
(1 row)
```