Fixed #21039 -- Added AddIndexConcurrently/RemoveIndexConcurrently operations for PostgreSQL.

Thanks to Simon Charettes for review.

Co-Authored-By: Daniel Tao <daniel.tao@gmail.com>

3 files changed, 31 insertions, 5 deletions

diff --git a/django/db/backends/base/schema.py b/django/db/backends/base/schema.py
index 3540fd5d0d..efb291f4e6 100644
--- a/django/db/backends/base/schema.py
+++ b/django/db/backends/base/schema.py
@@ -959,9 +959,9 @@ class BaseDatabaseSchemaEditor:
             condition=(' WHERE ' + condition) if condition else '',
         )
 
-    def _delete_index_sql(self, model, name):
+    def _delete_index_sql(self, model, name, sql=None):
         return Statement(
-            self.sql_delete_index,
+            sql or self.sql_delete_index,
             table=Table(model._meta.db_table, self.quote_name),
             name=self.quote_name(name),
         )
diff --git a/django/db/backends/postgresql/schema.py b/django/db/backends/postgresql/schema.py
index eb5b182680..9384c5e3b2 100644
--- a/django/db/backends/postgresql/schema.py
+++ b/django/db/backends/postgresql/schema.py
@@ -13,7 +13,11 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
     sql_set_sequence_owner = 'ALTER SEQUENCE %(sequence)s OWNED BY %(table)s.%(column)s'
 
     sql_create_index = "CREATE INDEX %(name)s ON %(table)s%(using)s (%(columns)s)%(extra)s%(condition)s"
+    sql_create_index_concurrently = (
+        "CREATE INDEX CONCURRENTLY %(name)s ON %(table)s%(using)s (%(columns)s)%(extra)s%(condition)s"
+    )
     sql_delete_index = "DROP INDEX IF EXISTS %(name)s"
+    sql_delete_index_concurrently = "DROP INDEX CONCURRENTLY IF EXISTS %(name)s"
 
     sql_create_column_inline_fk = 'REFERENCES %(to_table)s(%(to_column)s)%(deferrable)s'
     # Setting the constraint to IMMEDIATE runs any deferred checks to allow
@@ -157,3 +161,24 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         if opclasses:
             return IndexColumns(table, columns, self.quote_name, col_suffixes=col_suffixes, opclasses=opclasses)
         return super()._index_columns(table, columns, col_suffixes, opclasses)
+
+    def add_index(self, model, index, concurrently=False):
+        self.execute(index.create_sql(model, self, concurrently=concurrently), params=None)
+
+    def remove_index(self, model, index, concurrently=False):
+        self.execute(index.remove_sql(model, self, concurrently=concurrently))
+
+    def _delete_index_sql(self, model, name, sql=None, concurrently=False):
+        sql = self.sql_delete_index_concurrently if concurrently else self.sql_delete_index
+        return super()._delete_index_sql(model, name, sql)
+
+    def _create_index_sql(
+        self, model, fields, *, name=None, suffix='', using='',
+        db_tablespace=None, col_suffixes=(), sql=None, opclasses=(),
+        condition=None, concurrently=False,
+    ):
+        sql = self.sql_create_index if not concurrently else self.sql_create_index_concurrently
+        return super()._create_index_sql(
+            model, fields, name=name, suffix=suffix, using=using, db_tablespace=db_tablespace,
+            col_suffixes=col_suffixes, sql=sql, opclasses=opclasses, condition=condition,
+        )
diff --git a/django/db/models/indexes.py b/django/db/models/indexes.py
index c093b45619..5154de056e 100644
--- a/django/db/models/indexes.py
+++ b/django/db/models/indexes.py
@@ -49,17 +49,18 @@ class Index:
         # it's handled outside of that class, the work is done here.
         return sql % tuple(map(schema_editor.quote_value, params))
 
-    def create_sql(self, model, schema_editor, using=''):
+    def create_sql(self, model, schema_editor, using='', **kwargs):
         fields = [model._meta.get_field(field_name) for field_name, _ in self.fields_orders]
         col_suffixes = [order[1] for order in self.fields_orders]
         condition = self._get_condition_sql(model, schema_editor)
         return schema_editor._create_index_sql(
             model, fields, name=self.name, using=using, db_tablespace=self.db_tablespace,
             col_suffixes=col_suffixes, opclasses=self.opclasses, condition=condition,
+            **kwargs,
         )
 
-    def remove_sql(self, model, schema_editor):
-        return schema_editor._delete_index_sql(model, self.name)
+    def remove_sql(self, model, schema_editor, **kwargs):
+        return schema_editor._delete_index_sql(model, self.name, **kwargs)
 
     def deconstruct(self):
         path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)