- Mapped state internals have been reworked to allow for a 50% reduction

in callcounts specific to the "expiration" of objects, as in
the "auto expire" feature of :meth:`.Session.commit` and
for :meth:`.Session.expire_all`, as well as in the "cleanup" step
which occurs when object states are garbage collected.
fixes #3307

1 files changed, 7 insertions, 3 deletions

diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 3df6dce7a..c47026969 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -2691,9 +2691,13 @@ def make_transient(instance):
     if s:
         s._expunge_state(state)
 
-    # remove expired state and
-    # deferred callables
-    state.callables.clear()
+    # remove expired state
+    state.expired_attributes.clear()
+
+    # remove deferred callables
+    if state.callables:
+        del state.callables
+
     if state.key:
         del state.key
     if state.deleted: