mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2025-12-02 00:01:29 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Fixed #16759 -- Remove use of __deepcopy__ in qs.clone()

Browse source 
The original problem was that queryset cloning was really expensive
when filtering with F() clauses. The __deepcopy__ went too deep copying
_meta attributes of the models used. To fix this the use of
__deepcopy__ in qs cloning was removed.

This commit results in some speed improvements across the djangobench
benchmark suite. Most query_* tests are 20-30% faster, save() is 50%
faster and finally complex filtering situations can see 2x to order
of magnitude improvments.

Thanks to Suor, Alex and lrekucki for valuable feedback.
This commit is contained in:
Anssi Kääriäinen 2012-06-02 04:13:36 +03:00
parent bb7f34d619
commit 23ca3a0194
4 changed files with 81 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

14
django/db/models/sql/query.py
View file

@ -279,13 +279,13 @@ class Query(object):
obj.select = self.select[:]
obj.related_select_cols = []
obj.tables = self.tables[:]
obj.where = copy.deepcopy(self.where, memo=memo)
obj.where = self.where.clone()
obj.where_class = self.where_class
if self.group_by is None:
obj.group_by = None
else:
obj.group_by = self.group_by[:]
obj.having = copy.deepcopy(self.having, memo=memo)
obj.having = self.having.clone()
obj.order_by = self.order_by[:]
obj.low_mark, obj.high_mark = self.low_mark, self.high_mark
obj.distinct = self.distinct
@ -293,7 +293,9 @@ class Query(object):
obj.select_for_update = self.select_for_update
obj.select_for_update_nowait = self.select_for_update_nowait
obj.select_related = self.select_related
obj.aggregates = copy.deepcopy(self.aggregates, memo=memo)
obj.related_select_cols = []
obj.aggregates = SortedDict((k, v.clone())
for k, v in self.aggregates.items())
if self.aggregate_select_mask is None:
obj.aggregate_select_mask = None
else:
@ -316,7 +318,7 @@ class Query(object):
obj._extra_select_cache = self._extra_select_cache.copy()
obj.extra_tables = self.extra_tables
obj.extra_order_by = self.extra_order_by
obj.deferred_loading = copy.deepcopy(self.deferred_loading, memo=memo)
obj.deferred_loading = copy.copy(self.deferred_loading[0]), self.deferred_loading[1]
if self.filter_is_sticky and self.used_aliases:
obj.used_aliases = self.used_aliases.copy()
else:
@ -549,7 +551,7 @@ class Query(object):
# Now relabel a copy of the rhs where-clause and add it to the current
# one.
if rhs.where:
w = copy.deepcopy(rhs.where)
w = rhs.where.clone()
w.relabel_aliases(change_map)
if not self.where:
# Since 'self' matches everything, add an explicit "include
@ -571,7 +573,7 @@ class Query(object):
new_col = change_map.get(col[0], col[0]), col[1]
self.select.append(SelectInfo(new_col, field))
else:
item = copy.deepcopy(col)
item = col.clone()
item.relabel_aliases(change_map)
self.select.append(SelectInfo(item, field))