Fixed #29614 -- Added BTreeIndex to django.contrib.postres.

5 files changed, 86 insertions, 5 deletions

diff --git a/django/contrib/postgres/indexes.py b/django/contrib/postgres/indexes.py
index 7c41c7f340..34e09b19f2 100644
--- a/django/contrib/postgres/indexes.py
+++ b/django/contrib/postgres/indexes.py
@@ -1,7 +1,10 @@
 from django.db.models import Index
 from django.utils.functional import cached_property
 
-__all__ = ['BrinIndex', 'GinIndex', 'GistIndex', 'HashIndex', 'SpGistIndex']
+__all__ = [
+    'BrinIndex', 'BTreeIndex', 'GinIndex', 'GistIndex', 'HashIndex',
+    'SpGistIndex',
+]
 
 
 class PostgresIndex(Index):
@@ -55,6 +58,26 @@ class BrinIndex(PostgresIndex):
         return with_params
 
 
+class BTreeIndex(PostgresIndex):
+    suffix = 'btree'
+
+    def __init__(self, *, fillfactor=None, **kwargs):
+        self.fillfactor = fillfactor
+        super().__init__(**kwargs)
+
+    def deconstruct(self):
+        path, args, kwargs = super().deconstruct()
+        if self.fillfactor is not None:
+            kwargs['fillfactor'] = self.fillfactor
+        return path, args, kwargs
+
+    def get_with_params(self):
+        with_params = []
+        if self.fillfactor is not None:
+            with_params.append('fillfactor = %d' % self.fillfactor)
+        return with_params
+
+
 class GinIndex(PostgresIndex):
     suffix = 'gin'
 
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
index a24e37b0b8..584a2e86b6 100644
--- a/django/db/backends/postgresql/introspection.py
+++ b/django/db/backends/postgresql/introspection.py
@@ -200,6 +200,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
         """, [table_name])
         for index, columns, unique, primary, orders, type_, definition, options in cursor.fetchall():
             if index not in constraints:
+                basic_index = type_ == 'btree' and not index.endswith('_btree') and options is None
                 constraints[index] = {
                     "columns": columns if columns != [None] else [],
                     "orders": orders if orders != [None] else [],
@@ -208,7 +209,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
                     "foreign_key": None,
                     "check": False,
                     "index": True,
-                    "type": Index.suffix if type_ == 'btree' else type_,
+                    "type": Index.suffix if basic_index else type_,
                     "definition": definition,
                     "options": options,
                 }
diff --git a/docs/ref/contrib/postgres/indexes.txt b/docs/ref/contrib/postgres/indexes.txt
index cb0decc9a1..ef19384fb8 100644
--- a/docs/ref/contrib/postgres/indexes.txt
+++ b/docs/ref/contrib/postgres/indexes.txt
@@ -26,6 +26,20 @@ available from the ``django.contrib.postgres.indexes`` module.
 
         The ``autosummarize`` parameter was added.
 
+``BTreeIndex``
+==============
+
+.. class:: BTreeIndex(fillfactor=None, **options)
+
+    .. versionadded:: 2.2
+
+    Creates a B-Tree 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.
+
+    .. _fillfactor: https://www.postgresql.org/docs/current/static/sql-createindex.html#SQL-CREATEINDEX-STORAGE-PARAMETERS
+
 ``GinIndex``
 ============
 
diff --git a/docs/releases/2.2.txt b/docs/releases/2.2.txt
index 161f477695..13dac6bfec 100644
--- a/docs/releases/2.2.txt
+++ b/docs/releases/2.2.txt
@@ -82,9 +82,10 @@ Minor features
   :class:`~django.contrib.postgres.aggregates.StringAgg` determines the
   ordering of the aggregated elements.
 
-* The new :class:`~django.contrib.postgres.indexes.HashIndex` and
+* The new :class:`~django.contrib.postgres.indexes.BTreeIndex`,
+  :class:`~django.contrib.postgres.indexes.HashIndex` and
   :class:`~django.contrib.postgres.indexes.SpGistIndex` classes allow
-  creating ``hash`` and ``SP-GiST`` indexes in the database.
+  creating ``B-Tree``, ``hash``, and ``SP-GiST`` indexes in the database.
 
 * :class:`~django.contrib.postgres.indexes.BrinIndex` now has the
   ``autosummarize`` parameter.
diff --git a/tests/postgres_tests/test_indexes.py b/tests/postgres_tests/test_indexes.py
index 9bca4510fe..96ff829807 100644
--- a/tests/postgres_tests/test_indexes.py
+++ b/tests/postgres_tests/test_indexes.py
@@ -1,5 +1,5 @@
 from django.contrib.postgres.indexes import (
-    BrinIndex, GinIndex, GistIndex, HashIndex, SpGistIndex,
+    BrinIndex, BTreeIndex, GinIndex, GistIndex, HashIndex, SpGistIndex,
 )
 from django.db import connection
 from django.test import skipUnlessDBFeature
@@ -47,6 +47,20 @@ class BrinIndexTests(IndexTestMixin, PostgreSQLTestCase):
             BrinIndex(fields=['title'], name='test_title_brin', pages_per_range=0)
 
 
+class BTreeIndexTests(IndexTestMixin, PostgreSQLTestCase):
+    index_class = BTreeIndex
+
+    def test_suffix(self):
+        self.assertEqual(BTreeIndex.suffix, 'btree')
+
+    def test_deconstruction(self):
+        index = BTreeIndex(fields=['title'], name='test_title_btree', fillfactor=80)
+        path, args, kwargs = index.deconstruct()
+        self.assertEqual(path, 'django.contrib.postgres.indexes.BTreeIndex')
+        self.assertEqual(args, ())
+        self.assertEqual(kwargs, {'fields': ['title'], 'name': 'test_title_btree', 'fillfactor': 80})
+
+
 class GinIndexTests(IndexTestMixin, PostgreSQLTestCase):
     index_class = GinIndex
 
@@ -194,6 +208,34 @@ class SchemaTests(PostgreSQLTestCase):
             editor.remove_index(CharFieldModel, index)
         self.assertNotIn(index_name, self.get_constraints(CharFieldModel._meta.db_table))
 
+    def test_btree_index(self):
+        # Ensure the table is there and doesn't have an index.
+        self.assertNotIn('field', self.get_constraints(CharFieldModel._meta.db_table))
+        # Add the index.
+        index_name = 'char_field_model_field_btree'
+        index = BTreeIndex(fields=['field'], name=index_name)
+        with connection.schema_editor() as editor:
+            editor.add_index(CharFieldModel, index)
+        constraints = self.get_constraints(CharFieldModel._meta.db_table)
+        # The index was added.
+        self.assertEqual(constraints[index_name]['type'], BTreeIndex.suffix)
+        # Drop the index.
+        with connection.schema_editor() as editor:
+            editor.remove_index(CharFieldModel, index)
+        self.assertNotIn(index_name, self.get_constraints(CharFieldModel._meta.db_table))
+
+    def test_btree_parameters(self):
+        index_name = 'integer_array_btree_fillfactor'
+        index = BTreeIndex(fields=['field'], name=index_name, fillfactor=80)
+        with connection.schema_editor() as editor:
+            editor.add_index(CharFieldModel, index)
+        constraints = self.get_constraints(CharFieldModel._meta.db_table)
+        self.assertEqual(constraints[index_name]['type'], BTreeIndex.suffix)
+        self.assertEqual(constraints[index_name]['options'], ['fillfactor=80'])
+        with connection.schema_editor() as editor:
+            editor.remove_index(CharFieldModel, index)
+        self.assertNotIn(index_name, self.get_constraints(CharFieldModel._meta.db_table))
+
     def test_gist_index(self):
         # Ensure the table is there and doesn't have an index.
         self.assertNotIn('field', self.get_constraints(CharFieldModel._meta.db_table))