diff --git a/AUTHORS b/AUTHORS index 8486283a337..460bb9a7df3 100644 --- a/AUTHORS +++ b/AUTHORS @@ -214,6 +214,7 @@ answer newbie questions, and generally made Django that much better: Daniel Poelzleithner Daniel Pyrathon Daniel Roseman + Daniel Tao Daniel Wiesmann Danilo Bargen Dan Johnson diff --git a/django/contrib/postgres/indexes.py b/django/contrib/postgres/indexes.py index 7a5023c758f..526e729f2a1 100644 --- a/django/contrib/postgres/indexes.py +++ b/django/contrib/postgres/indexes.py @@ -18,9 +18,9 @@ class PostgresIndex(Index): # indexes. return Index.max_name_length - len(Index.suffix) + len(self.suffix) - def create_sql(self, model, schema_editor, using=''): + def create_sql(self, model, schema_editor, using='', **kwargs): self.check_supported(schema_editor) - statement = super().create_sql(model, schema_editor, using=' USING %s' % self.suffix) + statement = super().create_sql(model, schema_editor, using=' USING %s' % self.suffix, **kwargs) with_params = self.get_with_params() if with_params: statement.parts['extra'] = 'WITH (%s) %s' % ( diff --git a/django/contrib/postgres/operations.py b/django/contrib/postgres/operations.py index 95e7edcdea1..9e417725ec6 100644 --- a/django/contrib/postgres/operations.py +++ b/django/contrib/postgres/operations.py @@ -1,7 +1,9 @@ from django.contrib.postgres.signals import ( get_citext_oids, get_hstore_oids, register_type_handlers, ) +from django.db.migrations import AddIndex, RemoveIndex from django.db.migrations.operations.base import Operation +from django.db.utils import NotSupportedError class CreateExtension(Operation): @@ -75,3 +77,61 @@ class UnaccentExtension(CreateExtension): def __init__(self): self.name = 'unaccent' + + +class NotInTransactionMixin: + def _ensure_not_in_transaction(self, schema_editor): + if schema_editor.connection.in_atomic_block: + raise NotSupportedError( + 'The %s operation cannot be executed inside a transaction ' + '(set atomic = False on the migration).' + % self.__class__.__name__ + ) + + +class AddIndexConcurrently(NotInTransactionMixin, AddIndex): + """Create an index using PostgreSQL's CREATE INDEX CONCURRENTLY syntax.""" + atomic = False + + def describe(self): + return 'Concurrently create index %s on field(s) %s of model %s' % ( + self.index.name, + ', '.join(self.index.fields), + self.model_name, + ) + + def database_forwards(self, app_label, schema_editor, from_state, to_state): + self._ensure_not_in_transaction(schema_editor) + model = to_state.apps.get_model(app_label, self.model_name) + if self.allow_migrate_model(schema_editor.connection.alias, model): + schema_editor.add_index(model, self.index, concurrently=True) + + def database_backwards(self, app_label, schema_editor, from_state, to_state): + self._ensure_not_in_transaction(schema_editor) + model = from_state.apps.get_model(app_label, self.model_name) + if self.allow_migrate_model(schema_editor.connection.alias, model): + schema_editor.remove_index(model, self.index, concurrently=True) + + +class RemoveIndexConcurrently(NotInTransactionMixin, RemoveIndex): + """Remove an index using PostgreSQL's DROP INDEX CONCURRENTLY syntax.""" + atomic = False + + def describe(self): + return 'Concurrently remove index %s from %s' % (self.name, self.model_name) + + def database_forwards(self, app_label, schema_editor, from_state, to_state): + self._ensure_not_in_transaction(schema_editor) + model = from_state.apps.get_model(app_label, self.model_name) + if self.allow_migrate_model(schema_editor.connection.alias, model): + from_model_state = from_state.models[app_label, self.model_name_lower] + index = from_model_state.get_index_by_name(self.name) + schema_editor.remove_index(model, index, concurrently=True) + + def database_backwards(self, app_label, schema_editor, from_state, to_state): + self._ensure_not_in_transaction(schema_editor) + model = to_state.apps.get_model(app_label, self.model_name) + if self.allow_migrate_model(schema_editor.connection.alias, model): + to_model_state = to_state.models[app_label, self.model_name_lower] + index = to_model_state.get_index_by_name(self.name) + schema_editor.add_index(model, index, concurrently=True) diff --git a/django/db/backends/base/schema.py b/django/db/backends/base/schema.py index 3540fd5d0dd..efb291f4e64 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 eb5b182680f..9384c5e3b25 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 c093b45619f..5154de056e6 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__) diff --git a/docs/ref/contrib/postgres/operations.txt b/docs/ref/contrib/postgres/operations.txt index c56693478f5..1329ff1f9ea 100644 --- a/docs/ref/contrib/postgres/operations.txt +++ b/docs/ref/contrib/postgres/operations.txt @@ -98,3 +98,33 @@ run the query ``CREATE EXTENSION IF NOT EXISTS hstore;``. .. 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 `_. + +.. 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 + `_. + +.. note:: + + The ``CONCURRENTLY`` option is not supported inside a transaction (see + :ref:`non-atomic migration `). diff --git a/docs/releases/3.0.txt b/docs/releases/3.0.txt index 5bb0691363f..9489a38ca78 100644 --- a/docs/releases/3.0.txt +++ b/docs/releases/3.0.txt @@ -153,6 +153,10 @@ Minor features * The new :class:`~django.contrib.postgres.fields.RangeBoundary` expression represents the range boundaries. +* The new :class:`~django.contrib.postgres.operations.AddIndexConcurrently` + and :class:`~django.contrib.postgres.operations.RemoveIndexConcurrently` + classes allow creating and dropping indexes ``CONCURRENTLY`` on PostgreSQL. + :mod:`django.contrib.redirects` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/tests/migrations/test_base.py b/tests/migrations/test_base.py index 7c1cf82e169..94ff6ff0c9c 100644 --- a/tests/migrations/test_base.py +++ b/tests/migrations/test_base.py @@ -13,8 +13,6 @@ from django.test import TransactionTestCase from django.test.utils import extend_sys_path from django.utils.module_loading import module_dir -from .models import FoodManager, FoodQuerySet - class MigrationTestBase(TransactionTestCase): """ @@ -57,14 +55,14 @@ class MigrationTestBase(TransactionTestCase): def assertColumnNotNull(self, table, column, using='default'): self.assertEqual(self._get_column_allows_null(table, column, using), False) - def assertIndexExists(self, table, columns, value=True, using='default'): + def assertIndexExists(self, table, columns, value=True, using='default', index_type=None): with connections[using].cursor() as cursor: self.assertEqual( value, any( c["index"] for c in connections[using].introspection.get_constraints(cursor, table).values() - if c['columns'] == list(columns) + if c['columns'] == list(columns) and (index_type is None or c['type'] == index_type) ), ) @@ -266,6 +264,7 @@ class OperationTestBase(MigrationTestBase): bases=['%s.Pony' % app_label], )) if manager_model: + from .models import FoodManager, FoodQuerySet operations.append(migrations.CreateModel( 'Food', fields=[ diff --git a/tests/postgres_tests/test_operations.py b/tests/postgres_tests/test_operations.py new file mode 100644 index 00000000000..7be6de9effc --- /dev/null +++ b/tests/postgres_tests/test_operations.py @@ -0,0 +1,144 @@ +import unittest + +from migrations.test_base import OperationTestBase + +from django.db import connection, models +from django.db.models import Index +from django.db.utils import NotSupportedError +from django.test import modify_settings + +try: + from django.contrib.postgres.operations import ( + AddIndexConcurrently, RemoveIndexConcurrently, + ) + from django.contrib.postgres.indexes import BrinIndex, BTreeIndex +except ImportError: + pass + + +@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.') +@modify_settings(INSTALLED_APPS={'append': 'migrations'}) +class AddIndexConcurrentlyTests(OperationTestBase): + app_label = 'test_add_concurrently' + + def test_requires_atomic_false(self): + project_state = self.set_up_test_model(self.app_label) + new_state = project_state.clone() + operation = AddIndexConcurrently( + 'Pony', + models.Index(fields=['pink'], name='pony_pink_idx'), + ) + msg = ( + 'The AddIndexConcurrently operation cannot be executed inside ' + 'a transaction (set atomic = False on the migration).' + ) + with self.assertRaisesMessage(NotSupportedError, msg): + with connection.schema_editor(atomic=True) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + + def test_add(self): + project_state = self.set_up_test_model(self.app_label, index=False) + table_name = '%s_pony' % self.app_label + index = Index(fields=['pink'], name='pony_pink_idx') + new_state = project_state.clone() + operation = AddIndexConcurrently('Pony', index) + self.assertEqual( + operation.describe(), + 'Concurrently create index pony_pink_idx on field(s) pink of ' + 'model Pony' + ) + operation.state_forwards(self.app_label, new_state) + self.assertEqual(len(new_state.models[self.app_label, 'pony'].options['indexes']), 1) + self.assertIndexNotExists(table_name, ['pink']) + # Add index. + with connection.schema_editor(atomic=False) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + self.assertIndexExists(table_name, ['pink']) + # Reversal. + with connection.schema_editor(atomic=False) as editor: + operation.database_backwards(self.app_label, editor, new_state, project_state) + self.assertIndexNotExists(table_name, ['pink']) + # Deconstruction. + name, args, kwargs = operation.deconstruct() + self.assertEqual(name, 'AddIndexConcurrently') + self.assertEqual(args, []) + self.assertEqual(kwargs, {'model_name': 'Pony', 'index': index}) + + def test_add_other_index_type(self): + project_state = self.set_up_test_model(self.app_label, index=False) + table_name = '%s_pony' % self.app_label + new_state = project_state.clone() + operation = AddIndexConcurrently( + 'Pony', + BrinIndex(fields=['pink'], name='pony_pink_brin_idx'), + ) + self.assertIndexNotExists(table_name, ['pink']) + # Add index. + with connection.schema_editor(atomic=False) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + self.assertIndexExists(table_name, ['pink'], index_type='brin') + # Reversal. + with connection.schema_editor(atomic=False) as editor: + operation.database_backwards(self.app_label, editor, new_state, project_state) + self.assertIndexNotExists(table_name, ['pink']) + + def test_add_with_options(self): + project_state = self.set_up_test_model(self.app_label, index=False) + table_name = '%s_pony' % self.app_label + new_state = project_state.clone() + index = BTreeIndex(fields=['pink'], name='pony_pink_btree_idx', fillfactor=70) + operation = AddIndexConcurrently('Pony', index) + self.assertIndexNotExists(table_name, ['pink']) + # Add index. + with connection.schema_editor(atomic=False) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + self.assertIndexExists(table_name, ['pink'], index_type='btree') + # Reversal. + with connection.schema_editor(atomic=False) as editor: + operation.database_backwards(self.app_label, editor, new_state, project_state) + self.assertIndexNotExists(table_name, ['pink']) + + +@unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests.') +@modify_settings(INSTALLED_APPS={'append': 'migrations'}) +class RemoveIndexConcurrentlyTests(OperationTestBase): + app_label = 'test_rm_concurrently' + + def test_requires_atomic_false(self): + project_state = self.set_up_test_model(self.app_label, index=True) + new_state = project_state.clone() + operation = RemoveIndexConcurrently('Pony', 'pony_pink_idx') + msg = ( + 'The RemoveIndexConcurrently operation cannot be executed inside ' + 'a transaction (set atomic = False on the migration).' + ) + with self.assertRaisesMessage(NotSupportedError, msg): + with connection.schema_editor(atomic=True) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + + def test_remove(self): + project_state = self.set_up_test_model(self.app_label, index=True) + table_name = '%s_pony' % self.app_label + self.assertTableExists(table_name) + new_state = project_state.clone() + operation = RemoveIndexConcurrently('Pony', 'pony_pink_idx') + self.assertEqual( + operation.describe(), + 'Concurrently remove index pony_pink_idx from Pony', + ) + operation.state_forwards(self.app_label, new_state) + self.assertEqual(len(new_state.models[self.app_label, 'pony'].options['indexes']), 0) + self.assertIndexExists(table_name, ['pink']) + # Remove index. + with connection.schema_editor(atomic=False) as editor: + operation.database_forwards(self.app_label, editor, project_state, new_state) + self.assertIndexNotExists(table_name, ['pink']) + # Reversal. + with connection.schema_editor(atomic=False) as editor: + operation.database_backwards(self.app_label, editor, new_state, project_state) + self.assertIndexExists(table_name, ['pink']) + # Deconstruction. + name, args, kwargs = operation.deconstruct() + self.assertEqual(name, 'RemoveIndexConcurrently') + self.assertEqual(args, []) + self.assertEqual(kwargs, {'model_name': 'Pony', 'name': 'pony_pink_idx'})