db.collection.reIndex.txt

=======================
db.collection.reIndex()
=======================

.. default-domain:: mongodb

.. contents:: On this page
   :local:
   :backlinks: none
   :depth: 1
   :class: singlecol

Definition
----------

.. method:: db.collection.reIndex()
   
   .. deprecated:: 6.0
   
   Attempting to run the :method:`db.collection.reIndex()` method 
   writes a warning message to the log.

   .. |dbcommand| replace:: :dbcommand:`reIndex` command
   .. include:: /includes/fact-mongosh-shell-method-alt

   The :method:`db.collection.reIndex()` drops all indexes on a
   collection and recreates them. This operation may be expensive for
   collections that have a large amount of data and/or a large number
   of indexes.

   .. warning::

      - :method:`db.collection.reIndex()` may only be run on 
        :term:`standalone` instances. 
      - For most users, the :method:`db.collection.reIndex()` command 
        is unnecessary.


Compatibility
-------------

.. |command| replace:: method

This method is available in deployments hosted in the following environments: 

.. include:: /includes/fact-environments-atlas-only.rst

.. include:: /includes/fact-environments-atlas-support-no-free.rst

.. include:: /includes/fact-environments-onprem-only.rst

        
Behavior
--------

For MongoDB 5.0 or later, :method:`db.collection.reIndex()` may only be 
run on :term:`standalone` instances.

Resource Locking
~~~~~~~~~~~~~~~~

:method:`db.collection.reIndex()` obtains an exclusive (W) lock on the 
collection and blocks other operations on the collection until it completes.

For more information on locking in MongoDB, see :doc:`/faq/concurrency`.

.. seealso::

   :doc:`/indexes`