From ee9f4686b19e2b4a68f5cb4f9d61dc045c1d4c63 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Anssi=20K=C3=A4=C3=A4ri=C3=A4inen?= Date: Tue, 29 Dec 2015 18:29:11 +0200 Subject: [PATCH] Fixed #23372 -- Made loaddata faster if it doesn't find any fixtures. Django's test suite often tries to load fixture files from apps that have no fixtures at all. This creates a lot of unnecessary disabling and enabling of constraints which can be expensive on some database. To speed this up, loaddata now first checks if any fixture file matches. If no fixture file is matched, then the command exits before disabling and enabling of constraints is done. The main benefit of this change is seen on MSSQL, where tests on Django 1.8 run hours faster. --- django/core/management/commands/loaddata.py | 10 ++++++++++ docs/releases/1.8.8.txt | 3 +++ docs/releases/1.9.1.txt | 3 +++ tests/fixtures/tests.py | 14 +++++++++++++- 4 files changed, 29 insertions(+), 1 deletion(-) diff --git a/django/core/management/commands/loaddata.py b/django/core/management/commands/loaddata.py index af108e08e1..d384ea4c7e 100644 --- a/django/core/management/commands/loaddata.py +++ b/django/core/management/commands/loaddata.py @@ -85,6 +85,16 @@ class Command(BaseCommand): if has_bz2: self.compression_formats['bz2'] = (bz2.BZ2File, 'r') + # Django's test suite repeatedly tries to load initial_data fixtures + # from apps that don't have any fixtures. Because disabling constraint + # checks can be expensive on some database (especially MSSQL), bail + # out early if no fixtures are found. + for fixture_label in fixture_labels: + if self.find_fixtures(fixture_label): + break + else: + return + with connection.constraint_checks_disabled(): for fixture_label in fixture_labels: self.load_label(fixture_label) diff --git a/docs/releases/1.8.8.txt b/docs/releases/1.8.8.txt index 8caf5f7ff5..a888925841 100644 --- a/docs/releases/1.8.8.txt +++ b/docs/releases/1.8.8.txt @@ -51,3 +51,6 @@ Bugfixes * Fixed a regression in the admin which ignored line breaks in read-only fields instead of converting them to ``
`` (:ticket:`25465`). + +* Made ``loaddata`` skip disabling and enabling database constraints when it + doesn't load any fixtures (:ticket:`23372`). diff --git a/docs/releases/1.9.1.txt b/docs/releases/1.9.1.txt index 9af92e30ef..a01eb09d19 100644 --- a/docs/releases/1.9.1.txt +++ b/docs/releases/1.9.1.txt @@ -73,3 +73,6 @@ Bugfixes * Fixed incorrect object reference in ``SingleObjectMixin.get_context_object_name()`` (:ticket:`26006`). + +* Made ``loaddata`` skip disabling and enabling database constraints when it + doesn't load any fixtures (:ticket:`23372`). diff --git a/tests/fixtures/tests.py b/tests/fixtures/tests.py index f48a689f6f..86164e03bc 100644 --- a/tests/fixtures/tests.py +++ b/tests/fixtures/tests.py @@ -13,7 +13,7 @@ from django.core.files.temp import NamedTemporaryFile from django.core.serializers.base import ProgressBar from django.db import IntegrityError, connection from django.test import ( - TestCase, TransactionTestCase, ignore_warnings, skipUnlessDBFeature, + TestCase, TransactionTestCase, ignore_warnings, mock, skipUnlessDBFeature, ) from django.utils import six from django.utils.encoding import force_text @@ -643,6 +643,18 @@ class NonExistentFixtureTests(TestCase): self.assertEqual(force_text(w[0].message), "No fixture named 'this_fixture_doesnt_exist' found.") + @mock.patch('django.db.connection.enable_constraint_checking') + @mock.patch('django.db.connection.disable_constraint_checking') + def test_nonexistent_fixture_no_constraint_checking(self, + disable_constraint_checking, enable_constraint_checking): + """ + If no fixtures match the loaddata command, constraints checks on the + database shouldn't be disabled. This is performance critical on MSSQL. + """ + management.call_command('loaddata', 'this_fixture_doesnt_exist', verbosity=0) + disable_constraint_checking.assert_not_called() + enable_constraint_checking.assert_not_called() + class FixtureTransactionTests(DumpDataAssertMixin, TransactionTestCase):