> ## Documentation Index > Fetch the complete documentation index at: https://elementary-more-explicit-webhook-instructions.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # column_anomalies `elementary.column_anomalies` Executes column level monitors and anomaly detection on the column. Specific monitors are detailed in the table below and can be configured using the `columns_anomalies` configuration. The test checks the data type of the column and only executes monitors that are relevant to it. ### Test configuration No mandatory configuration, however it is highly recommended to configure a `timestamp_column`. {/* prettier-ignore */} 
  
    tests:
      -- elementary.column\_anomalies:
        column\_anomalies: column monitors list
        timestamp\_column: column name
        where\_expression: sql expression
        anomaly\_sensitivity: int
        anomaly\_direction: \[both | spike | drop]
        detection\_period:
          period: \[hour | day | week | month]
          count: int
        training\_period:
          period: \[hour | day | week | month]
          count: int
        time\_bucket:
          period: \[hour | day | week | month]
          count: int
        seasonality: day\_of\_week
        detection\_delay:
          period: \[hour | day | week | month]
          count: int
        ignore\_small\_changes:
          spike\_failure\_percent\_threshold: int
          drop\_failure\_percent\_threshold: int
        anomaly\_exclude\_metrics: \[SQL expression]
```yml Models models: - name: < model name > config: elementary: timestamp_column: < timestamp column > columns: - name: < column name > tests: - elementary.column_anomalies: column_anomalies: < specific monitors, all if null > where_expression: < sql expression > time_bucket: # Daily by default period: < time period > count: < number of periods > - name: < model name > ## if no timestamp is configured, elementary will monitor without time filtering columns: - name: < column name > tests: - elementary.column_anomalies: column_anomalies: < specific monitors, all if null > where_expression: < sql expression > ``` ```yml Models example models: - name: login_events config: elementary: timestamp_column: 'loaded_at' columns: - name: user_name tests: - elementary.column_anomalies: column_anomalies: - missing_count - min_length where_expression: "event_type in ('event_1', 'event_2') and country_name != 'unwanted country'" time_bucket: period: day count: 1 tags: ['elementary'] - name: users ## if no timestamp is configured, elementary will monitor without time filtering tests: elementary.volume_anomalies tags: ['elementary'] columns: - name: user_id tests: - elementary.column_anomalies: tags: ['elementary'] timestamp_column: 'updated_at' where_expression: "event_type in ('event_1', 'event_2') and country_name != 'unwanted country'" time_bucket: period: < time period > count: < number of periods > - name: user_name tests: - elementary.column_anomalies: column_anomalies: - missing_count - min_length tags: ['elementary'] ```