Tests params
backfill_days

backfill_days: [int]

Configuration to define the detection period. If the backfill_days are set to 2, only data points in the last 2 days will be included in the detection period and could be flagged anomalous. If backfill_days is set to 7 days, the detection period will be 7 days long.

For incremental models, this is also the period for re-calculating metrics. If metrics for buckets in the backfill days were already calculated, Elementary will overwrite them. The reason behind it is to monitor recent backfills of data, if there were any. This configuration should be changed according to your data delays.

  • Default: 2
  • Relevant tests: Anomaly detection tests with timestamp_column
backfill_days change impact

backfill_days change impact

models:
  - name: this_is_a_model
    tests:
      - elementary.volume_anomalies:
          backfill_days: 7

‚Äč
How it works?

The backfill_days param only works for tests that have timestamp_column configuration.

It works differently according to the table materialization:

  • Regular tables and views - backfill_days defines the detection period.
  • Incremental models and sources - backfill_days defines the detection period, and the period for which metrics will be re-calculated.