From 7f4e17451135a8aee597e24aac4670a6d8860047 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dra=C5=BEen=20Odoba=C5=A1i=C4=87?= Date: Sun, 19 Nov 2017 10:13:10 -0500 Subject: [PATCH] [1.11.x] Fixed #28817 -- Made QuerySet.iterator() use server-side cursors after values() and values_list(). Backport of d97f026a7ab5212192426e45121f7a52751a2044 from master --- django/db/models/query.py | 8 ++++---- django/db/models/sql/compiler.py | 4 ++-- docs/releases/1.11.8.txt | 3 +++ tests/backends/test_postgresql.py | 15 ++++++++++++++- 4 files changed, 23 insertions(+), 7 deletions(-) diff --git a/django/db/models/query.py b/django/db/models/query.py index 8a97e45b88..379edf3882 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -103,7 +103,7 @@ class ValuesIterable(BaseIterable): # extra(select=...) cols are always at the start of the row. names = extra_names + field_names + annotation_names - for row in compiler.results_iter(): + for row in compiler.results_iter(chunked_fetch=self.chunked_fetch): yield dict(zip(names, row)) @@ -119,7 +119,7 @@ class ValuesListIterable(BaseIterable): compiler = query.get_compiler(queryset.db) if not query.extra_select and not query.annotation_select: - for row in compiler.results_iter(): + for row in compiler.results_iter(chunked_fetch=self.chunked_fetch): yield tuple(row) else: field_names = list(query.values_select) @@ -135,7 +135,7 @@ class ValuesListIterable(BaseIterable): else: fields = names - for row in compiler.results_iter(): + for row in compiler.results_iter(chunked_fetch=self.chunked_fetch): data = dict(zip(names, row)) yield tuple(data[f] for f in fields) @@ -149,7 +149,7 @@ class FlatValuesListIterable(BaseIterable): def __iter__(self): queryset = self.queryset compiler = queryset.query.get_compiler(queryset.db) - for row in compiler.results_iter(): + for row in compiler.results_iter(chunked_fetch=self.chunked_fetch): yield row[0] diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py index 9888816c8d..e40770c151 100644 --- a/django/db/models/sql/compiler.py +++ b/django/db/models/sql/compiler.py @@ -833,12 +833,12 @@ class SQLCompiler(object): row[pos] = value return tuple(row) - def results_iter(self, results=None): + def results_iter(self, results=None, chunked_fetch=False): """ Returns an iterator over the results from executing this query. """ if results is None: - results = self.execute_sql(MULTI) + results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch) fields = [s[0] for s in self.select[0:self.col_count]] converters = self.get_converters(fields) for rows in results: diff --git a/docs/releases/1.11.8.txt b/docs/releases/1.11.8.txt index 426b6d92b2..89b6e5ed52 100644 --- a/docs/releases/1.11.8.txt +++ b/docs/releases/1.11.8.txt @@ -18,3 +18,6 @@ Bugfixes * Fixed incorrect index name truncation when using a namespaced ``db_table`` (:ticket:`28792`). + +* Made ``QuerySet.iterator()`` use server-side cursors on PostgreSQL after + ``values()`` and ``values_list()`` (:ticket:`28817`). diff --git a/tests/backends/test_postgresql.py b/tests/backends/test_postgresql.py index 8ea8638306..2efec5eef2 100644 --- a/tests/backends/test_postgresql.py +++ b/tests/backends/test_postgresql.py @@ -3,7 +3,7 @@ import unittest from collections import namedtuple from contextlib import contextmanager -from django.db import connection +from django.db import connection, models from django.test import TestCase from .models import Person @@ -53,6 +53,19 @@ class ServerSideCursorsPostgres(TestCase): def test_server_side_cursor(self): self.assertUsesCursor(Person.objects.iterator()) + def test_values(self): + self.assertUsesCursor(Person.objects.values('first_name').iterator()) + + def test_values_list(self): + self.assertUsesCursor(Person.objects.values_list('first_name').iterator()) + + def test_values_list_flat(self): + self.assertUsesCursor(Person.objects.values_list('first_name', flat=True).iterator()) + + def test_values_list_fields_not_equal_to_names(self): + expr = models.Count('id') + self.assertUsesCursor(Person.objects.annotate(id__count1=expr).values_list(expr, 'id__count1').iterator()) + def test_server_side_cursor_many_cursors(self): persons = Person.objects.iterator() persons2 = Person.objects.iterator()