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authorMariusz Felisiak <felisiak.mariusz@gmail.com>2024-01-13 14:33:20 -0500
committerMariusz Felisiak <felisiak.mariusz@gmail.com>2024-01-15 05:56:38 +0100
commitf3d10546a850df4fe3796f972d5b7e16adf52f54 (patch)
tree91bf01575742ce83d2dd38f10fa0f03451e8ef49 /django/db/models/sql/query.py
parentd074c7530b812a7b78c9a201c8a70f281ed3a36e (diff)
Refs #35102 -- Optimized replace_expressions()/relabelling aliases by adding early return.
This avoids costly hashing. Thanks Anthony Shaw for the report. Co-Authored-By: Simon Charette <charette.s@gmail.com>
Diffstat (limited to 'django/db/models/sql/query.py')
-rw-r--r--django/db/models/sql/query.py2
1 files changed, 2 insertions, 0 deletions
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index a79d66eb21..ce4fafb1e2 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -972,6 +972,8 @@ class Query(BaseExpression):
relabelling any references to them in select columns and the where
clause.
"""
+ if not change_map:
+ return self
# If keys and values of change_map were to intersect, an alias might be
# updated twice (e.g. T4 -> T5, T5 -> T6, so also T4 -> T6) depending
# on their order in change_map.