Once you’ve set up the basic Elementary components — the dbt package and CLI — you can start adding Elementary tests to your data. You can add Elementary tests once completing the initial setup or later as you identify critical tables and metrics. Many teams start with a few volume or freshness tests, then expand coverage as needed. Elementary data tests include flexible anomaly detection tests, schema changes and Python tests, configured and executed like native tests in your dbt project. Elementary tests can be used in addition to dbt tests, packages tests (such as dbt-expectations), and custom tests. All test results will be presented in the Elementary UI and alerts.

Anomaly detection

  • Volume
  • Freshness
  • Event freshness
  • Column anomalies
  • Dimensions

Schema tests

  • Schema changes
  • Baseline schema
  • JSON schema
  • Exposure schema

Other tests

  • Python tests

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Anomaly detection tests

Tests to detect anomalies in data quality metrics such as volume, freshness, null rates, and anomalies in specific dimensions.
How Elementary anomaly detection tests work?

Volume anomalies

Monitors table row count over time to detect drops or spikes in volume.

Freshness anomalies

Monitors the latest timestamp of a table to detect data delays.

Event freshness anomalies

Monitors the gap between the latest event timestamp and its loading time, to detect event freshness issues.

Dimension anomalies

Monitors the row count per dimension over time, and alerts on unexpected changes in the distribution. It is best to configure it on low-cardinality fields.

All columns anomalies

Activates the column anomalies test on all the columns of the table. It’s possible to exclude specific columns.

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Schema tests

Schema changes

Fails on changes in schema: deleted or added columns, or change of data type of a column.

Schema changes from baseline

Fails if the table schema is different in columns names or column types than a configured baseline (can be generated with a macro).

JSON schema

Monitors a JSON type column and fails if there are JSON events that don’t match a configured JSON schema (can be generated with a macro).

Exposure schema

Monitors changes in your models’ columns that break schema for downstream exposures, such as BI dashboards.

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Other tests

Python tests

Write your own custom tests using Python scripts.