************************
Collection Configuration
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.. default-domain:: mongodb

.. contents:: On this page
   :local:
   :backlinks: none
   :depth: 2
   :class: singlecol

Configuring a Document Collection
=================================

You can specify collection options for documents using the ``store_in`` macro.
This macro accepts ``:collection_options`` argument, which can contain any collection
options that are supported by the driver.

.. note::

  In order to apply the options, the collection must be explicitly created up-front.
  This should be done using  :ref:`Collection Management Rake Task<collection-management-task>`.

Please refer to `the driver collections page
<https://mongodb.com/docs/ruby-driver/current/reference/collection-tasks/>`_
for the more information about collection options.

.. note::

  Collection options depend on the driver version and MongoDB server version.
  It is possible that some options, like time series collections, are not available
  on older server versions.

Time Series Collection
----------------------

.. code-block:: ruby

  class Measurement
    include Mongoid::Document

    field :temperature, type: Integer
    field :timestamp, type: Time

    store_in collection_options: {
      time_series: {
        timeField: "timestamp",
        granularity: "minutes"
      },
      expire_after: 604800
    }
  end



Capped Collections
------------------

.. code-block:: ruby

  class Name
    include Mongoid::Document

    store_in collection_options: {
      capped: true,
      size: 1024
    }
  end

Set a Default Collation on a Collection
---------------------------------------

.. code-block:: ruby

  class Name
    include Mongoid::Document

    store_in collection_options: {
      collation: {
        locale: 'fr'
      }
    }
  end

.. _collection-management-task:

Collection Management Rake Task
===============================

If you specify collection options for a document, then the corresponding collection
must be explicitly created prior to use. To do so, use the provided
``db:mongoid:create_collections`` Rake task:

.. code-block:: bash

    $ rake db:mongoid:create_collections

The create collections command also works for just one model by running
in Rails console:

.. code-block:: ruby

    # Create collection for Model
    Model.create_collection