Schema Management

Atlas SQL schemas are JSON schemas that describe data as it exists in MongoDB, including its polymorphism, sparseness, and nested, structured data. Atlas Data Federation can automatically generate a schema by sampling data from documents in your collection or view.

Atlas Data Federation automatically generates a schema for a collection or view in the storage configuration when you:

• Create the collection or view in the storage configuration.

• Rename a collection or view that does not already have a schema. If you rename a collection or view that already has a schema, the schema is also renamed. Atlas Data Federation does not generate a new schema for a renamed collection or view if it already exists.

• Set the storage configuration.

In addition, for wildcard (*) collections, Atlas Data Federation generates a schema when it discovers the collections in the namespace catalog for the wildcard (*) collections.

You can manually generate schemas for all collections and views using the sqlGenerateSchema command, set or update the schema for your collections or views using the sqlSetSchema command, and view the stored schema using the sqlGetSchema command.

You can manually delete a schema for a collection or view by running the sqlSetSchema command with an empty schema document. Data Federation automatically removes the schema for a collection or view when you:

• Drop the collection or view from the storage configuration.

• Modify the storage configuration to remove the collection or view from the storage configuration.

• Drop the database that contains the collection or view from the storage configuration.

In addition, for a wildcard (*) collection, Atlas Data Federation deletes the schema when it discovers that the collection has been removed from the namespace catalog.