Fixed #25175 -- Renamed the postgresql_psycopg2 database backend to postgresql.

django/contrib/gis/db/backends/postgis/base.py

 from django.db.backends.base.base import NO_DB_ALIAS
-from django.db.backends.postgresql_psycopg2.base import \
+from django.db.backends.postgresql.base import \
     DatabaseWrapper as Psycopg2DatabaseWrapper
 
 from .features import DatabaseFeatures

django/contrib/gis/db/backends/postgis/features.py

 from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
-from django.db.backends.postgresql_psycopg2.features import \
+from django.db.backends.postgresql.features import \
     DatabaseFeatures as Psycopg2DatabaseFeatures
 
 

django/contrib/gis/db/backends/postgis/introspection.py

 from django.contrib.gis.gdal import OGRGeomType
-from django.db.backends.postgresql_psycopg2.introspection import \
-    DatabaseIntrospection
+from django.db.backends.postgresql.introspection import DatabaseIntrospection
 
 
 class GeoIntrospectionError(Exception):

django/contrib/gis/db/backends/postgis/operations.py

@@ -11,8 +11,7 @@ from django.contrib.gis.db.backends.utils import SpatialOperator
 from django.contrib.gis.geometry.backend import Geometry
 from django.contrib.gis.measure import Distance
 from django.core.exceptions import ImproperlyConfigured
-from django.db.backends.postgresql_psycopg2.operations import \
-    DatabaseOperations
+from django.db.backends.postgresql.operations import DatabaseOperations
 from django.db.utils import ProgrammingError
 from django.utils.functional import cached_property
 

django/contrib/gis/db/backends/postgis/schema.py

-from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
+from django.db.backends.postgresql.schema import DatabaseSchemaEditor
 
 
 class PostGISSchemaEditor(DatabaseSchemaEditor):

django/db/utils.py

@@ -104,7 +104,14 @@ class DatabaseErrorWrapper(object):
 
 
 def load_backend(backend_name):
-    # Look for a fully qualified database backend name
+    """
+    Return a database backend's "base" module given a fully qualified database
+    backend name, or raise an error if it doesn't exist.
+    """
+    # This backend was renamed in Django 1.9.
+    if backend_name == 'django.db.backends.postgresql_psycopg2':
+        backend_name = 'django.db.backends.postgresql'
+
     try:
         return import_module('%s.base' % backend_name)
     except ImportError as e_user:
@@ -114,7 +121,8 @@ def load_backend(backend_name):
         try:
             builtin_backends = [
                 name for _, name, ispkg in pkgutil.iter_modules([npath(backend_dir)])
-                if ispkg and name not in {'base', 'dummy'}]
+                if ispkg and name not in {'base', 'dummy', 'postgresql_psycopg2'}
+            ]
         except EnvironmentError:
             builtin_backends = []
         if backend_name not in ['django.db.backends.%s' % b for b in

docs/intro/tutorial02.txt

@@ -26,7 +26,7 @@ settings:
 
 * :setting:`ENGINE <DATABASE-ENGINE>` -- Either
   ``'django.db.backends.sqlite3'``,
-  ``'django.db.backends.postgresql_psycopg2'``,
+  ``'django.db.backends.postgresql'``,
   ``'django.db.backends.mysql'``, or
   ``'django.db.backends.oracle'``. Other backends are :ref:`also available
   <third-party-notes>`.

docs/ref/models/querysets.txt

@@ -1512,7 +1512,7 @@ make the call non-blocking. If a conflicting lock is already acquired by
 another transaction, :exc:`~django.db.DatabaseError` will be raised when the
 queryset is evaluated.
 
-Currently, the ``postgresql_psycopg2``, ``oracle``, and ``mysql`` database
+Currently, the ``postgresql``, ``oracle``, and ``mysql`` database
 backends support ``select_for_update()``. However, MySQL has no support for the
 ``nowait`` argument. Obviously, users of external third-party backends should
 check with their backend's documentation for specifics in those cases.

docs/ref/settings.txt

@@ -459,7 +459,7 @@ other database types. This example is for PostgreSQL::
 
     DATABASES = {
         'default': {
-            'ENGINE': 'django.db.backends.postgresql_psycopg2',
+            'ENGINE': 'django.db.backends.postgresql',
             'NAME': 'mydatabase',
             'USER': 'mydatabaseuser',
             'PASSWORD': 'mypassword',
@@ -500,14 +500,19 @@ Default: ``''`` (Empty string)
 
 The database backend to use. The built-in database backends are:
 
-* ``'django.db.backends.postgresql_psycopg2'``
+* ``'django.db.backends.postgresql'``
 * ``'django.db.backends.mysql'``
 * ``'django.db.backends.sqlite3'``
 * ``'django.db.backends.oracle'``
 
 You can use a database backend that doesn't ship with Django by setting
-``ENGINE`` to a fully-qualified path (i.e.
-``mypackage.backends.whatever``).
+``ENGINE`` to a fully-qualified path (i.e. ``mypackage.backends.whatever``).
+
+.. versionchanged:: 1.9
+
+    The ``django.db.backends.postgresql`` backend is named
+    ``django.db.backends.postgresql_psycopg2`` in older releases. For backwards
+    compatibility, the old name still works in newer versions.
 
 .. setting:: HOST
 
@@ -657,8 +662,7 @@ The character set encoding used to create the test database. The value of this
 string is passed directly through to the database, so its format is
 backend-specific.
 
-Supported for the PostgreSQL_ (``postgresql_psycopg2``) and MySQL_ (``mysql``)
-backends.
+Supported by the PostgreSQL_ (``postgresql``) and MySQL_ (``mysql``) backends.
 
 .. _PostgreSQL: http://www.postgresql.org/docs/current/static/multibyte.html
 .. _MySQL: http://dev.mysql.com/doc/refman/5.6/en/charset-database.html

docs/ref/signals.txt

@@ -625,7 +625,7 @@ Arguments sent with this signal:
 
 ``sender``
     The database wrapper class -- i.e.
-    ``django.db.backends.postgresql_psycopg2.DatabaseWrapper`` or
+    ``django.db.backends.postgresql.DatabaseWrapper`` or
     ``django.db.backends.mysql.DatabaseWrapper``, etc.
 
 ``connection``

docs/releases/1.9.txt

@@ -578,6 +578,13 @@ Validators
 * Added :func:`~django.core.validators.validate_unicode_slug` to validate slugs
   that may contain Unicode characters.
 
+Database backends
+^^^^^^^^^^^^^^^^^
+
+* The PostgreSQL backend (``django.db.backends.postgresql_psycopg2``) is also
+  available as ``django.db.backends.postgresql``. The old name will continue to
+  be available for backwards compatibility.
+
 Backwards incompatible changes in 1.9
 =====================================
 

docs/topics/db/multi-db.txt

@@ -29,7 +29,7 @@ databases -- a default PostgreSQL database and a MySQL database called
     DATABASES = {
         'default': {
             'NAME': 'app_data',
-            'ENGINE': 'django.db.backends.postgresql_psycopg2',
+            'ENGINE': 'django.db.backends.postgresql',
             'USER': 'postgres_user',
             'PASSWORD': 's3krit'
         },

tests/backends/test_utils.py

@@ -9,7 +9,7 @@ class TestLoadBackend(SimpleTestCase):
         msg = (
             "'foo' isn't an available database backend.\n"
             "Try using 'django.db.backends.XXX', where XXX is one of:\n"
-            "    'mysql', 'oracle', 'postgresql_psycopg2', 'sqlite3'\n"
+            "    'mysql', 'oracle', 'postgresql', 'sqlite3'\n"
             "Error was: No module named %s"
         ) % "foo.base" if six.PY2 else "'foo'"
         with self.assertRaisesMessage(ImproperlyConfigured, msg):

tests/backends/tests.py

@@ -18,7 +18,7 @@ from django.db import (
     reset_queries, transaction,
 )
 from django.db.backends.base.base import BaseDatabaseWrapper
-from django.db.backends.postgresql_psycopg2 import version as pg_version
+from django.db.backends.postgresql import version as pg_version
 from django.db.backends.signals import connection_created
 from django.db.backends.utils import CursorWrapper, format_number
 from django.db.models import Avg, StdDev, Sum, Variance
@@ -313,7 +313,7 @@ class PostgreSQLTests(TestCase):
         self.assertEqual(a[0], b[0])
 
     def test_lookup_cast(self):
-        from django.db.backends.postgresql_psycopg2.operations import DatabaseOperations
+        from django.db.backends.postgresql.operations import DatabaseOperations
 
         do = DatabaseOperations(connection=None)
         for lookup in ('iexact', 'contains', 'icontains', 'startswith',
@@ -321,8 +321,8 @@ class PostgreSQLTests(TestCase):
             self.assertIn('::text', do.lookup_cast(lookup))
 
     def test_correct_extraction_psycopg2_version(self):
-        from django.db.backends.postgresql_psycopg2.base import psycopg2_version
-        version_path = 'django.db.backends.postgresql_psycopg2.base.Database.__version__'
+        from django.db.backends.postgresql.base import psycopg2_version
+        version_path = 'django.db.backends.postgresql.base.Database.__version__'
 
         with mock.patch(version_path, '2.6.9'):
             self.assertEqual(psycopg2_version(), (2, 6, 9))

tests/dbshell/test_postgresql_psycopg2.py

@@ -4,7 +4,7 @@ from __future__ import unicode_literals
 import locale
 import os
 
-from django.db.backends.postgresql_psycopg2.client import DatabaseClient
+from django.db.backends.postgresql.client import DatabaseClient
 from django.test import SimpleTestCase, mock
 from django.utils import six
 from django.utils.encoding import force_bytes, force_str