mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2025-08-03 18:38:50 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Improved Query join promotion logic

Browse source 
There were multiple cases where join promotion was a bit too aggressive.
This resulted in using outer joins where not necessary.

Refs #21150.
This commit is contained in:
Anssi Kääriäinen 2013-09-24 19:37:55 +03:00
parent ed0d720b78
commit ecaba36028
4 changed files with 136 additions and 52 deletions
Download patch file Download diff file Expand all files Collapse all files

47
tests/queries/tests.py
View file

@ -2689,6 +2689,15 @@ class NullJoinPromotionOrTest(TestCase):
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
self.assertEqual(list(qs), [self.a2])
def test_null_join_demotion(self):
qs = ModelA.objects.filter(Q(b__name__isnull=False) & Q(b__name__isnull=True))
self.assertTrue(' INNER JOIN ' in str(qs.query))
qs = ModelA.objects.filter(Q(b__name__isnull=True) & Q(b__name__isnull=False))
self.assertTrue(' INNER JOIN ' in str(qs.query))
qs = ModelA.objects.filter(Q(b__name__isnull=False) | Q(b__name__isnull=True))
self.assertTrue(' LEFT OUTER JOIN ' in str(qs.query))
qs = ModelA.objects.filter(Q(b__name__isnull=True) | Q(b__name__isnull=False))
self.assertTrue(' LEFT OUTER JOIN ' in str(qs.query))
class ReverseJoinTrimmingTest(TestCase):
def test_reverse_trimming(self):
@ -2785,22 +2794,19 @@ class DisjunctionPromotionTests(TestCase):
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 1)
@unittest.expectedFailure
def test_disjunction_promotion3_failing(self):
# Now the ORed filter creates LOUTER join, but we do not have
# logic to unpromote it for the AND filter after it. The query
# results will be correct, but we have one LOUTER JOIN too much
# currently.
def test_disjunction_promotion3_demote(self):
# This one needs demotion logic: the first filter causes a to be
# outer joined, the second filter makes it inner join again.
qs = BaseA.objects.filter(
Q(a__f1='foo') | Q(b__f2='foo')).filter(a__f2='bar')
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 1)
@unittest.expectedFailure
def test_disjunction_promotion4_failing(self):
# Failure because no join repromotion
def test_disjunction_promotion4_demote(self):
qs = BaseA.objects.filter(Q(a=1) | Q(a=2))
self.assertEqual(str(qs.query).count('JOIN'), 0)
# Demote needed for the "a" join. It is marked as outer join by
# above filter (even if it is trimmed away).
qs = qs.filter(a__f1='foo')
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
@ -2810,9 +2816,8 @@ class DisjunctionPromotionTests(TestCase):
qs = qs.filter(Q(a=1) | Q(a=2))
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
@unittest.expectedFailure
def test_disjunction_promotion5_failing(self):
# Failure because no join repromotion logic.
def test_disjunction_promotion5_demote(self):
# Failure because no join demotion logic for this case.
qs = BaseA.objects.filter(Q(a=1) | Q(a=2))
# Note that the above filters on a force the join to an
# inner join even if it is trimmed.
@ -2823,8 +2828,8 @@ class DisjunctionPromotionTests(TestCase):
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 1)
qs = BaseA.objects.filter(Q(a__f1='foo') | Q(b__f1='foo'))
# Now the join to a is created as LOUTER
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 0)
qs = qs.objects.filter(Q(a=1) | Q(a=2))
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 2)
qs = qs.filter(Q(a=1) | Q(a=2))
self.assertEqual(str(qs.query).count('INNER JOIN'), 1)
self.assertEqual(str(qs.query).count('LEFT OUTER JOIN'), 1)
@ -3079,3 +3084,17 @@ class Ticket21203Tests(TestCase):
qs = Ticket21203Child.objects.select_related('parent').defer('parent__created')
self.assertQuerysetEqual(qs, [c], lambda x: x)
self.assertIs(qs[0].parent.parent_bool, True)
class ValuesJoinPromotionTests(TestCase):
def test_values_no_promotion_for_existing(self):
qs = Node.objects.filter(parent__parent__isnull=False)
self.assertTrue(' INNER JOIN ' in str(qs.query))
qs = qs.values('parent__parent__id')
self.assertTrue(' INNER JOIN ' in str(qs.query))
# Make sure there is a left outer join without the filter.
qs = Node.objects.values('parent__parent__id')
self.assertTrue(' LEFT OUTER JOIN ' in str(qs.query))
def test_non_nullable_fk_not_promoted(self):
qs = ObjectB.objects.values('objecta__name')
self.assertTrue(' INNER JOIN ' in str(qs.query))