System Collections

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• Synopsis

• Collections

  Synopsis

MongoDB stores system information in collections that use the <database>.system.* namespace, which MongoDB reserves for internal use. Do not create collections that begin with system.

MongoDB also stores some additional instance-local metadata in the local database, specifically for replication purposes and in the config database for sessions information.

Collections

System collections include these collections stored in the admin database:

• admin.system.``roles

  The admin.system.roles collection stores custom roles that administrators create and assign to users to provide access to specific resources.

• admin.system.``users

  The admin.system.users collection stores the user’s authentication credentials as well as any roles assigned to the user. Users may define authorization roles in the admin.system.roles collection.

• admin.system.``version

  Stores the schema version of the user credential documents.

System collections include these collections stored in the config database:

• config.system.``indexBuilds

  New in version 4.4.The indexBuilds collection stores information related to in-progress index builds.

System collections also include these collections stored directly in each database:

• <database>.system.``namespaces

  REMOVED IN 4.2Starting in MongoDB 4.2, <database>.system.namespaces has been removed (access to the collection has been deprecated since 3.0). To list the collections in a database, use the listCollections command instead.

• <database>.system.``indexes

  REMOVED IN 4.2Starting in MongoDB 4.2, <database>.system.indexes has been removed (access to the collection has been deprecated since 3.0). To list the inndexes, use the listIndexes command instead.

• <database>.system.``profile

  The .system.profile collection stores database profiling information. For information on profiling, see Database Profiling.

• <database>.system.``js

  The .system.js collection holds special JavaScript code for use in server side JavaScript. See Store a JavaScript Function on the Server for more information.

• <database>.system.``views

  The .system.views collection contains information about each view in the database.

  参见

原文 - System Collections