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

# dimensions

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`dimensions: [list of SQL expressions]`

The test will group the results by a given column / columns / valid select sql expression.
Under `dimensions` you can configure the group by expression.

Using this param segments the tested data per dimension, and each dimension is monitored separately.

For example -
A `column_anomalies` test monitoring for `null_rate` with `dimensions` configured will monitor the
`null_rate` of values in the column, grouped by dimension, and will fail if in a specific dimension there is an anomaly in `null_rate`.
It is best to configure low-cardinality fields as `dimensions`.

* *Default: None*
* *Relevant tests: `dimension_anomalies`, `column_anomalies`, `all_columns_anomalies`*
* *Configuration level: test*

<RequestExample>
  ```yml test theme={null}
  models:
    - name: model_name
      config:
        elementary:
          timestamp_column: updated_at
      data_tests:
        - elementary.dimension_anomalies:
            arguments:
              dimensions:
                - device_os
                - device_browser
  ```
</RequestExample>