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System Collections¶
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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.
Collections¶
System collections include these collections stored directly in the database:
-
<database>.system.namespaces¶ The
<database>.system.namespacescollection contains information about all of the database’s collections. Additional namespace metadata exists in thedatabase.nsfiles and is opaque to database users.
-
<database>.system.indexes¶ The
<database>.system.indexescollection lists all the indexes in the database. Add and remove data from this collection via theensureIndex()anddropIndex()
-
<database>.system.profile¶ The
<database>.system.profilecollection stores database profiling information. For information on profiling, see Database Profiling.
-
<database>.system.users The
<database>.system.userscollection stores credentials for users who have access to the database. For more information on this collection, see Add a User to a Database and<database>.system.users.
-
<database>.system.js¶ The
<database>.system.jscollection holds special JavaScript code for use in server side JavaScript. See Store a JavaScript Function on the Server for more information.