> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# $extendedStats

`$extendedStats` returns `$stats` plus additional distribution metrics.

In addition to `count`, `sum`, `min`, `max`, and `avg`, this operator provides:

* `sumOfSquares`
* `variance`, `variancePopulation`, `varianceSampling`
* `stdDeviation`, `stdDeviationPopulation`, `stdDeviationSampling`
* `stdDeviationBounds` (`upper`, `lower`, plus sampling/population variants)

`sigma` controls the width of `stdDeviationBounds`.

### Compatibility

| Field Type | Supported |
| - | - |
| TEXT | No |
| U64/I64/F64 | Yes |
| DATE | Yes |
| BOOL | No |
| KEYWORD | No |
| FACET | No |

Field must be `FAST`.

### Arguments

| Argument | Type | Required | Description |
| - | - | - | - |
| `field` | `string` | Yes | Field to aggregate. |
| `missing` | `number` | No | Fallback value for missing fields. |
| `sigma` | `number` | No | Multiplier used for standard deviation bounds. |

> [tab] TypeScript
>
> ```ts theme={"system"}
> await index.aggregate({
>   aggregations: {
>     price_extended: {
>       $extendedStats: { field: "price", sigma: 2, missing: 0 },
>     },
>   },
> });
> ```

> [tab] Python
>
> ```python theme={"system"}
> index.aggregate(
>     aggregations={
>         "price_extended": {
>             "$extendedStats": {"field": "price", "sigma": 2, "missing": 0}
>         }
>     }
> )
> ```

> [tab] Redis CLI
>
> ```bash theme={"system"}
> SEARCH.AGGREGATE products '{}' '{"price_extended": {"$extendedStats": {"field": "price", "sigma": 2, "missing": 0}}}'
> ```

### Output

Returns a single object containing all basic and extended fields. Example shape:

```json theme={"system"}
{ "price_extended": {
    "count": 9, "min": 0, "max": 80, "avg": 40, "sum": 360,
    "sumOfSquares": 18000, "variance": 200, "stdDeviation": 14.14,
    "stdDeviationBounds": { "upper": 68.28, "lower": 11.72 }
  }
}
```


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.