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django/docs/ref/contrib/postgres/indexes.txt

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=================================
PostgreSQL specific model indexes
=================================
.. module:: django.contrib.postgres.indexes
The following are PostgreSQL specific :doc:`indexes </ref/models/indexes>`
available from the ``django.contrib.postgres.indexes`` module.
``BrinIndex``
=============
.. class:: BrinIndex(pages_per_range=None, **options)
Creates a `BRIN index
<https://www.postgresql.org/docs/current/static/brin-intro.html>`_.
The ``pages_per_range`` argument takes a positive integer.
``GinIndex``
============
.. class:: GinIndex(fastupdate=None, gin_pending_list_limit=None, **options)
Creates a `gin index
<https://www.postgresql.org/docs/current/static/gin.html>`_.
To use this index on data types not in the `built-in operator classes
<https://www.postgresql.org/docs/current/static/gin-builtin-opclasses.html>`_,
you need to activate the `btree_gin extension
<https://www.postgresql.org/docs/current/static/btree-gin.html>`_ on
PostgreSQL. You can install it using the
:class:`~django.contrib.postgres.operations.BtreeGinExtension` migration
operation.
Set the ``fastupdate`` parameter to ``False`` to disable the `GIN Fast
Update Technique`_ that's enabled by default in PostgreSQL.
Provide an integer number of bytes to the gin_pending_list_limit_ parameter
to tune the maximum size of the GIN pending list which is used when
``fastupdate`` is enabled. This parameter requires PostgreSQL ≥ 9.5.
.. _GIN Fast Update Technique: https://www.postgresql.org/docs/current/static/gin-implementation.html#GIN-FAST-UPDATE
.. _gin_pending_list_limit: https://www.postgresql.org/docs/current/static/runtime-config-client.html#GUC-GIN-PENDING-LIST-LIMIT
.. versionchanged:: 2.0
The ``fastupdate`` and ``gin_pending_list_limit`` parameters were added.
``GistIndex``
=============
.. class:: GistIndex(buffering=None, fillfactor=None, **options)
.. versionadded:: 2.0
Creates a `GiST index
<https://www.postgresql.org/docs/current/static/gist.html>`_. These indexes
are automatically created on spatial fields with :attr:`spatial_index=True
<django.contrib.gis.db.models.BaseSpatialField.spatial_index>`. They're
also useful on other types, such as
:class:`~django.contrib.postgres.fields.HStoreField` or the :ref:`range
fields <range-fields>`.
To use this index on data types not in the built-in `gist operator classes
<https://www.postgresql.org/docs/current/static/gist-builtin-opclasses.html>`_,
you need to activate the `btree_gist extension
<https://www.postgresql.org/docs/current/static/btree-gist.html>`_ on
PostgreSQL. You can install it using the
:class:`~django.contrib.postgres.operations.BtreeGistExtension` migration
operation.
Set the ``buffering`` parameter to ``True`` or ``False`` to manually enable
or disable `buffering build`_ of the index.
Provide an integer value from 10 to 100 to the fillfactor_ parameter to
tune how packed the index pages will be. PostgreSQL's default is 90.
.. _buffering build: https://www.postgresql.org/docs/current/static/gist-implementation.html#GIST-BUFFERING-BUILD
.. _fillfactor: https://www.postgresql.org/docs/current/static/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS