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  • Use Cases
  • Create and Manage Views
  • Comparison with On-Demand Materialized Views
  • Behavior
  • Access Control

A MongoDB view is a read-only queryable object whose contents are defined by an aggregation pipeline on other collections or views.

MongoDB does not persist the view contents to disk. A view's content is computed on-demand when a client queries the view.



This page discusses standard views. For discussion of on-demand materialized views, see On-Demand Materialized Views.

To understand the differences between the view types, see Comparison with On-Demand Materialized Views.

You can use views to:

To learn how to create and manage views, see the following resources:

MongoDB provides two different view types: standard views and on-demand materialized views. Both view types return the results from an aggregation pipeline.

  • Standard views are computed when you read the view, and are not stored to disk.

  • On-demand materialized views are stored on and read from disk. They use a $merge or $out stage to update the saved data.


    When using $merge, you can use change streams to watch for changes on the materialized view. When using $out, you can't watch for changes on the materialized view.

Standard views use the indexes of the underlying collection. As a result, you cannot create, drop or re-build indexes on a standard view directly, nor get a list of indexes on the view.

You can create indexes directly on on-demand materialized views because they are stored on disk.

On-demand materialized views provide better read performance than standard views because they are read from disk instead of computed as part of the query. This performance benefit increases based on the complexity of the pipeline and size of the data being aggregated.

The following sections describe behavior specific to views.

Views are read-only. Write operations on views return an error.

Views do not maintain timestamps of collection changes and do not support point-in-time or snapshot read isolation.

The view's underlying aggregation pipeline is subject to the 100 megabyte memory limit for blocking sort and blocking group operations.

Starting in MongoDB 6.0, pipeline stages that require more than 100 megabytes of memory to execute write temporary files to disk by default. In earlier verisons of MongoDB, you must pass { allowDiskUse: true } to individual find and aggregate commands to enable this behavior.

Individual find and aggregate commands may override the allowDiskUseByDefault parameter by either:

  • Using { allowDiskUse: true } to allow writing temporary files out to disk when allowDiskUseByDefault is set to false

  • Using { allowDiskUse: false } to prohibit writing temporary files out to disk when allowDiskUseByDefault is set to true

  • Time series collections are writable non-materialized views. Limitations for views apply to time series collections. For more information, see Time Series Collection Limitations.

  • You cannot create a view from a time series bucket collection namespace (namely, a collection prefixed with system.buckets).


Do not attempt to create a time series collection or view with the name system.profile. MongoDB 6.3 and later versions return an IllegalOperation error if you attempt to do so. Earlier MongoDB versions crash.

If the deployment enforces authentication, db.createView() requires that the authenticated user have the createCollection privilege on the database.

However, if the user has the createCollection on the database and find on the view to create, the user must also have the following additional permissions:

  • find on the source collection or view.

  • find on any other collections or views referenced in the pipeline, if any.

A user with the readWrite built in role on the database has the required privileges to run the listed operations. Either create a user with the required role or grant the role to an existing user

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