title: 'Full Refresh Mode' sidebar_label: 'Full' description: 'Replace the entire accelerated dataset on each refresh.' sidebar_position: 1 pagination_prev: null pagination_next: null

The full refresh mode replaces the entire accelerated dataset on every refresh. It is the default refresh mode and the simplest way to keep an acceleration in sync with its source.

Use full when:

• The dataset is small enough to be re-read on each refresh.
• Source rows can be inserted, updated, or deleted, and incremental tracking is not available.
• Strong consistency with the source is preferred over minimizing source load.

Configuration

datasets:
  - from: databricks:my_dataset
    name: accelerated_dataset
    acceleration:
      enabled: true
      refresh_mode: full
      refresh_check_interval: 10m

datasets:
  - from: databricks:my_dataset
    name: accelerated_dataset
    acceleration:
      enabled: true
      refresh_mode: full
      refresh_check_interval: 10m

On each refresh, the runtime issues a single SELECT against the source, materializes the result into the acceleration engine, and atomically swaps the new data in.

Behavior

• Each refresh fully scans the source. Any refresh_sql (opens in a new tab) and refresh_data_window (opens in a new tab) filters are pushed down to limit data transferred.
• Queries continue to be served from the previous result set until the new refresh completes.
• Supported with all data connectors and all acceleration engines.
• On Iceberg (opens in a new tab) sources, the scan applies Iceberg v2 position and equality delete files, so a full refresh retracts rows that delete files have removed. append (opens in a new tab) does not. See Delete files on federated reads (opens in a new tab).

Cost and duration

A full refresh re-reads the configured source on every interval. Use refresh_sql (opens in a new tab) (and refresh_data_window (opens in a new tab)) to narrow what is downloaded and kept.

Inspect refresh duration in runtime.task_history (opens in a new tab) where task = 'acceleration_refresh', or the dataset_acceleration_refresh_duration_ms (opens in a new tab) histogram (Prometheus exposes the bucket series as dataset_acceleration_refresh_duration_ms_bucket).

Related Topics

For cross-cutting refresh behavior that applies to full mode, see:

• Refresh Interval (opens in a new tab)
• Refresh on Startup (opens in a new tab)
• Refresh Retries (opens in a new tab)
• Retention Policy (opens in a new tab)
• Behavior on Zero Results (opens in a new tab)