How do you rename a MongoDB database?

No there isn't. See https://jira.mongodb.org/browse/SERVER-701

Unfortunately, this is not an simple feature for us to implement due to the way that database metadata is stored in the original (default) storage engine. In MMAPv1 files, the namespace (e.g.: dbName.collection) that describes every single collection and index includes the database name, so to rename a set of database files, every single namespace string would have to be rewritten. This impacts:

  • the .ns file
  • every single numbered file for the collection
  • the namespace for every index
  • internal unique names of each collection and index
  • contents of system.namespaces and system.indexes (or their equivalents in the future)
  • other locations I may be missing

This is just to accomplish a rename of a single database in a standalone mongod instance. For replica sets the above would need to be done on every replica node, plus on each node every single oplog entry that refers this database would have to be somehow invalidated or rewritten, and then if it's a sharded cluster, one also needs to add these changes to every shard if the DB is sharded, plus the config servers have all the shard metadata in terms of namespaces with their full names.

There would be absolutely no way to do this on a live system.

To do it offline, it would require re-writing every single database file to accommodate the new name, and at that point it would be as slow as the current "copydb" command...


You could do this, if you're using MongoDB < 4.2 (ref):

db.copyDatabase("db_to_rename","db_renamed","localhost")
use db_to_rename
db.dropDatabase();

Editorial Note: this is the same approach used in the question itself but has proven useful to others regardless.


Alternative solution: you can dump your db and restore that in different name. As I've experienced it's much quicker than db.copyDatabase().

$ mongodump -d old_db_name -o mongodump/
$ mongorestore -d new_db_name mongodump/old_db_name

http://docs.mongodb.org/manual/tutorial/backup-with-mongodump/

This is the current official recommended approach for database renames, given that copyDatabase was removed in MongoDB 4.2:

The "copydb" command is deprecated, please use these two commands instead:

  1. mongodump (to back up data)
  2. mongorestore (to recover data from mongodump into a new namespace)

NOTE: Hopefully this changed in the latest version.

You cannot copy data between a MongoDB 4.0 mongod instance (regardless of the FCV value) and a MongoDB 3.4 and earlier mongod instance. https://docs.mongodb.com/v4.0/reference/method/db.copyDatabase/

ALERT: Hey folks just be careful while copying the database, if you don't want to mess up the different collections under single database.

The following shows you how to rename

> show dbs;
testing
games
movies

To rename you use the following syntax

db.copyDatabase("old db name","new db name")

Example:

db.copyDatabase('testing','newTesting')

Now you can safely delete the old db by the following way

use testing;

db.dropDatabase(); //Here the db **testing** is deleted successfully

Now just think what happens if you try renaming the new database name with existing database name

Example:

db.copyDatabase('testing','movies');

So in this context all the collections (tables) of testing will be copied to movies database.

Tags:

Database

Mongodb

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