- [removed] The legacy "mutable" system of the

ORM, including the MutableType class as well
as the mutable=True flag on PickleType
and postgresql.ARRAY has been removed.
In-place mutations are detected by the ORM
using the sqlalchemy.ext.mutable extension,
introduced in 0.7.   The removal of MutableType
and associated constructs removes a great
deal of complexity from SQLAlchemy's internals.
The approach performed poorly as it would incur
a scan of the full contents of the Session
when in use. [ticket:2442]

1 files changed, 1 insertions, 7 deletions

diff --git a/lib/sqlalchemy/orm/instrumentation.py b/lib/sqlalchemy/orm/instrumentation.py
index 1012af67a..e9d1ca36a 100644
--- a/lib/sqlalchemy/orm/instrumentation.py
+++ b/lib/sqlalchemy/orm/instrumentation.py
@@ -86,7 +86,6 @@ class ClassManager(dict):
         self.factory = None  # where we came from, for inheritance bookkeeping
         self.info = {}
         self.new_init = None
-        self.mutable_attributes = set()
         self.local_attrs = {}
         self.originals = {}
 
@@ -155,10 +154,7 @@ class ClassManager(dict):
     @util.memoized_property
     def _state_constructor(self):
         self.dispatch.first_init(self, self.class_)
-        if self.mutable_attributes:
-            return state.MutableAttrInstanceState
-        else:
-            return state.InstanceState
+        return state.InstanceState
 
     def manage(self):
         """Mark this instance as the manager for its class."""
@@ -209,8 +205,6 @@ class ClassManager(dict):
             del self.local_attrs[key]
             self.uninstall_descriptor(key)
         del self[key]
-        if key in self.mutable_attributes:
-            self.mutable_attributes.remove(key)
         for cls in self.class_.__subclasses__():
             manager = manager_of_class(cls) 
             if manager: