How to Move a MongoDB Collection Between Databases

If you need to move a collection between two MongoDB databases, there is no need to dump and restore your data using mongodump / mongorestore.

In a way, it's pretty similar to what we can do with  MySQL's "RENAME TABLE" command:

db.runCommand({renameCollection:"sourcedb.mycol",to:"targetdb.mycol"})

In the background, MongoDB will dump and restore it automatically. There is no metadata "magic" for such a rename since databases reside in different files on disk. It just saves a bit of work, and it's worth knowing about.