问题描述
现在一个实例里有 DBA, DBB, DBC, NewDB，如何把ABC导入到NewDB？结构是一样的，试过For Insert 和 InsertMany，但是数据有接近500W，插了没几条就不工作了。而且效率太低。请问有什么高效的办法吗？
问题解答
回答1：如果是复制集的话倒是有办法，不是十分直观不过我们有renameCollection Command:注意：务必读完上面的链接再动手。
{ renameCollection: '<source_namespace>', to: '<target_namespace>', dropTarget: <true|false> }FieldTypeDescriptionrenameCollectionstringThe namespace of the collection to rename. The namespace is a combination of the database name and the name of the collection.tostringThe new namespace of the collection. If the new namespace specifies a different database, the renameCollection command copies the collection to the new database and drops the source collection.dropTargetbooleanOptional. If true, mongod will drop the target of renameCollection prior to renaming the collection. The default value is false.
Example:
use admindb.runCommand( { renameCollection: 'DBA.xxx', to: 'NewDB.xxx' } )db.runCommand( { renameCollection: 'DBA.yyy', to: 'NewDB.yyy' } )...
