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

# About Filters

> Learn about the filter types available in Validio to specify which datapoints or records to include in validator calculations.

Use filters to specify the datapoints or records you want to include in a validator metric calculation or [segmentation](https://docs.validio.io/v10.0/docs/segmentation.md) fields. For a detailed reference of each filter type, see [Filter Types](https://docs.validio.io/v10.0/docs/filters/filter-types.md). The following table lists the types of filters that Validio supports:

| Filter Types | Description |
| :- | :- |
| No Filter | No filter applied to data. Process all available datapoints in a Window. |
| [Boolean Filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#boolean-filter) | Ensures that a Boolean value is either true or false. |
| [Enum Filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#enum-filter) | Ensures that a string only contains values from a fixed set of specified values. |
| [Null Filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#null-filter) | Ensures that a field value is NULL. |
| [String Filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#string-filter) | Ensures that a string adheres to certain criteria. |
| [SQL Filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#sql-filter) | Filter records based on a SQL WHERE statement. |
| [Threshold filter](https://docs.validio.io/v10.0/docs/filters/filter-types.md#threshold-filter) | Ensures that a numeric value is either under or over a certain threshold. |

## When to configure filters

You can configure filters on both validators and segmentations:

* **Configure filters on validators** to specify the datapoints to include in the metric calculation. For example, to count only the `NULL` values for a certain field, use a volume validator and apply a `NULL` filter.
* **Configure filters on segments** to specify the values to include in the segmentation. Because segments will be created before the validator metric, it’s better to apply filters related to the segments on the segmentation. Then, you can configure validators to use the filtered segmentation.