On this page
Auto-index creation for Performance Advisor periodically checks for index recommendations and automatically creates indexes deemed to have a high impact on cluster performance.
You can enable auto-index creation if your cluster meets all of the following criteria:
- Runs MongoDB 4.4 or later.
- Uses tiers
- Does not run as a sharded cluster.
Auto-index creation prioritizes creating indexes with the highest Impact score. Atlas defines impact as the estimated performance improvement that the index would bring.
To learn more about the Impact score and how the Performance Advisor ranks indexes, see Review Index Ranking.
Performance Advisor doesn't show individual index recommendations by default. Performance Advisor shows the number of index recommendations per impact level (high and medium). To view the individual indexes that the auto-index creation would create, click View Recommendations. Atlas only creates high-impact indexes automatically.
Auto-index creation defaults to off. You can enable auto-index creation for your cluster through either the Atlas console or Atlas Administration API.
Atlas sends an email alert when it creates an index automatically. You can view automatically created indexes from the Atlas UI Indexes view. The Atlas UI shows indexes that auto-index creation generated with the Auto-Created property.
You can drop auto-created indexes as you would any other index. To drop an auto-created index, click Drop Index. If you drop an auto-created index, auto-index creation doesn't recreate that index. Performance Advisor may still recommend that index.