This version of the documentation is archived and no longer
supported. View the current documentation to learn how to
upgrade your version of MongoDB.
Definition
Note
Removed in 5.0
Important
mongo Shell Method
This page documents the mongo shell method, and does
not refer to the MongoDB Node.js driver (or any other driver)
method. For corresponding MongoDB driver API, refer to your specific
MongoDB driver documentation instead.
Deprecated since version 3.0: db.collection.ensureIndex() has been replaced by
db.collection.createIndex().
Creates an index on the specified field if the index does not already exist.
Additional Information
Use
db.collection.createIndex()rather thandb.collection.ensureIndex()to create new indexes.The Indexes section of this manual for full documentation of indexes and indexing in MongoDB.
db.collection.getIndexes()to view the specifications of existing indexes for a collection.