Docs Menu

Docs HomeLaunch & Manage MongoDBMongoDB Atlas

Auto-Index Creation for Performance Advisor

On this page

  • Auto-Index Creation Availability
  • How Auto-Index Creation Creates Indexes
  • Enable Auto-Index Creation
  • Review Automatically Created Indexes
  • Drop Automatically Created Indexes

Auto-index creation for Performance Advisor periodically checks for index recommendations and automatically creates indexes deemed to have a high impact on cluster performance.

To learn about auto-index creation for serverless instances, see Auto-Create Indexes for Serverless Instances.

You can enable auto-index creation if your cluster meets all of the following criteria:

  • Runs MongoDB 5.0 or later.

  • Uses tiers M10 and M30 (inclusive).

  • 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 automatically created indexes 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 might still recommend that index.

What is MongoDB Atlas? →