mirror of
https://github.com/django/django.git
synced 2024-12-25 18:46:22 +00:00
131 lines
3.7 KiB
Plaintext
131 lines
3.7 KiB
Plaintext
=============================
|
|
Database migration operations
|
|
=============================
|
|
|
|
All of these :doc:`operations </ref/migration-operations>` are available from
|
|
the ``django.contrib.postgres.operations`` module.
|
|
|
|
.. _create-postgresql-extensions:
|
|
|
|
Creating extension using migrations
|
|
===================================
|
|
|
|
You can create a PostgreSQL extension in your database using a migration file.
|
|
This example creates an hstore extension, but the same principles apply for
|
|
other extensions.
|
|
|
|
Set up the hstore extension in PostgreSQL before the first ``CreateModel``
|
|
or ``AddField`` operation that involves
|
|
:class:`~django.contrib.postgres.fields.HStoreField` by adding a migration with
|
|
the :class:`~django.contrib.postgres.operations.HStoreExtension` operation.
|
|
For example::
|
|
|
|
from django.contrib.postgres.operations import HStoreExtension
|
|
|
|
class Migration(migrations.Migration):
|
|
...
|
|
|
|
operations = [
|
|
HStoreExtension(),
|
|
...
|
|
]
|
|
|
|
Creating the extension requires a database user with superuser privileges.
|
|
If the Django database user doesn't have superuser privileges, you'll have
|
|
to create the extension outside of Django migrations with a user that has
|
|
the appropriate privileges. In that case, connect to your Django database and
|
|
run the query ``CREATE EXTENSION IF NOT EXISTS hstore;``.
|
|
|
|
.. currentmodule:: django.contrib.postgres.operations
|
|
|
|
``CreateExtension``
|
|
===================
|
|
|
|
.. class:: CreateExtension(name)
|
|
|
|
An ``Operation`` subclass which installs PostgreSQL extensions.
|
|
|
|
.. attribute:: name
|
|
|
|
This is a required argument. The name of the extension to be installed.
|
|
|
|
``BtreeGinExtension``
|
|
=====================
|
|
|
|
.. class:: BtreeGinExtension()
|
|
|
|
Install the ``btree_gin`` extension.
|
|
|
|
``BtreeGistExtension``
|
|
======================
|
|
|
|
.. class:: BtreeGistExtension()
|
|
|
|
Install the ``btree_gist`` extension.
|
|
|
|
``CITextExtension``
|
|
===================
|
|
|
|
.. class:: CITextExtension()
|
|
|
|
Installs the ``citext`` extension.
|
|
|
|
``CryptoExtension``
|
|
===================
|
|
|
|
.. class:: CryptoExtension()
|
|
|
|
Installs the ``pgcrypto`` extension.
|
|
|
|
``HStoreExtension``
|
|
===================
|
|
|
|
.. class:: HStoreExtension()
|
|
|
|
Installs the ``hstore`` extension and also sets up the connection to
|
|
interpret hstore data for possible use in subsequent migrations.
|
|
|
|
``TrigramExtension``
|
|
====================
|
|
|
|
.. class:: TrigramExtension()
|
|
|
|
Installs the ``pg_trgm`` extension.
|
|
|
|
``UnaccentExtension``
|
|
=====================
|
|
|
|
.. class:: UnaccentExtension()
|
|
|
|
Installs the ``unaccent`` extension.
|
|
|
|
Index concurrent operations
|
|
===========================
|
|
|
|
.. versionadded:: 3.0
|
|
|
|
PostgreSQL supports the ``CONCURRENTLY`` option to ``CREATE INDEX`` and
|
|
``DROP INDEX`` statements to add and remove indexes without locking out writes.
|
|
This option is useful for adding or removing an index in a live production
|
|
database.
|
|
|
|
.. class:: AddIndexConcurrently(model_name, index)
|
|
|
|
Like :class:`~django.db.migrations.operations.AddIndex`, but creates an
|
|
index with the ``CONCURRENTLY`` option. This has a few caveats to be aware
|
|
of when using this option, see `the PostgreSQL documentation of building
|
|
indexes concurrently <https://www.postgresql.org/docs/current/
|
|
sql-createindex.html#SQL-CREATEINDEX-CONCURRENTLY>`_.
|
|
|
|
.. class:: RemoveIndexConcurrently(model_name, name)
|
|
|
|
Like :class:`~django.db.migrations.operations.RemoveIndex`, but removes the
|
|
index with the ``CONCURRENTLY`` option. This has a few caveats to be aware
|
|
of when using this option, see `the PostgreSQL documentation
|
|
<https://www.postgresql.org/docs/current/sql-dropindex.html>`_.
|
|
|
|
.. note::
|
|
|
|
The ``CONCURRENTLY`` option is not supported inside a transaction (see
|
|
:ref:`non-atomic migration <non-atomic-migrations>`).
|