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121 lines
4.7 KiB
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121 lines
4.7 KiB
Plaintext
=================================
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PostgreSQL specific model indexes
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=================================
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.. module:: django.contrib.postgres.indexes
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The following are PostgreSQL specific :doc:`indexes </ref/models/indexes>`
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available from the ``django.contrib.postgres.indexes`` module.
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``BrinIndex``
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=============
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.. class:: BrinIndex(autosummarize=None, pages_per_range=None, **options)
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Creates a `BRIN index
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<https://www.postgresql.org/docs/current/brin-intro.html>`_.
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Set the ``autosummarize`` parameter to ``True`` to enable `automatic
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summarization`_ to be performed by autovacuum.
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The ``pages_per_range`` argument takes a positive integer.
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.. _automatic summarization: https://www.postgresql.org/docs/current/brin-intro.html#BRIN-OPERATION
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``BTreeIndex``
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==============
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.. class:: BTreeIndex(fillfactor=None, **options)
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Creates a B-Tree index.
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Provide an integer value from 10 to 100 to the fillfactor_ parameter to
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tune how packed the index pages will be. PostgreSQL's default is 90.
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.. _fillfactor: https://www.postgresql.org/docs/current/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS
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``GinIndex``
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============
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.. class:: GinIndex(fastupdate=None, gin_pending_list_limit=None, **options)
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Creates a `gin index <https://www.postgresql.org/docs/current/gin.html>`_.
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To use this index on data types not in the `built-in operator classes
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<https://www.postgresql.org/docs/current/gin-builtin-opclasses.html>`_,
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you need to activate the `btree_gin extension
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<https://www.postgresql.org/docs/current/btree-gin.html>`_ on
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PostgreSQL. You can install it using the
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:class:`~django.contrib.postgres.operations.BtreeGinExtension` migration
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operation.
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Set the ``fastupdate`` parameter to ``False`` to disable the `GIN Fast
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Update Technique`_ that's enabled by default in PostgreSQL.
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Provide an integer number of bytes to the gin_pending_list_limit_ parameter
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to tune the maximum size of the GIN pending list which is used when
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``fastupdate`` is enabled.
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.. _GIN Fast Update Technique: https://www.postgresql.org/docs/current/gin-implementation.html#GIN-FAST-UPDATE
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.. _gin_pending_list_limit: https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-GIN-PENDING-LIST-LIMIT
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``GistIndex``
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=============
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.. class:: GistIndex(buffering=None, fillfactor=None, **options)
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Creates a `GiST index
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<https://www.postgresql.org/docs/current/gist.html>`_. These indexes are
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automatically created on spatial fields with :attr:`spatial_index=True
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<django.contrib.gis.db.models.BaseSpatialField.spatial_index>`. They're
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also useful on other types, such as
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:class:`~django.contrib.postgres.fields.HStoreField` or the :ref:`range
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fields <range-fields>`.
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To use this index on data types not in the built-in `gist operator classes
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<https://www.postgresql.org/docs/current/gist-builtin-opclasses.html>`_,
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you need to activate the `btree_gist extension
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<https://www.postgresql.org/docs/current/btree-gist.html>`_ on PostgreSQL.
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You can install it using the
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:class:`~django.contrib.postgres.operations.BtreeGistExtension` migration
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operation.
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Set the ``buffering`` parameter to ``True`` or ``False`` to manually enable
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or disable `buffering build`_ of the index.
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Provide an integer value from 10 to 100 to the fillfactor_ parameter to
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tune how packed the index pages will be. PostgreSQL's default is 90.
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.. _buffering build: https://www.postgresql.org/docs/current/gist-implementation.html#GIST-BUFFERING-BUILD
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.. _fillfactor: https://www.postgresql.org/docs/current/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS
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``HashIndex``
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=============
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.. class:: HashIndex(fillfactor=None, **options)
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Creates a hash index.
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Provide an integer value from 10 to 100 to the fillfactor_ parameter to
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tune how packed the index pages will be. PostgreSQL's default is 90.
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.. admonition:: Use this index only on PostgreSQL 10 and later
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Hash indexes have been available in PostgreSQL for a long time, but
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they suffer from a number of data integrity issues in older versions.
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.. _fillfactor: https://www.postgresql.org/docs/current/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS
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``SpGistIndex``
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===============
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.. class:: SpGistIndex(fillfactor=None, **options)
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Creates an `SP-GiST index
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<https://www.postgresql.org/docs/current/spgist.html>`_.
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Provide an integer value from 10 to 100 to the fillfactor_ parameter to
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tune how packed the index pages will be. PostgreSQL's default is 90.
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.. _fillfactor: https://www.postgresql.org/docs/current/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS
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