whereby a self referential relation
from a base class to a joined-table subclass would
not configure correctly.
+
+ - Fixed documentation for session weak_identity_map -
+ the default value is True, indicating a weak
+ referencing map in use.
- sql
- ``sqlalchemy.extract()`` is now dialect sensitive and can
before each transaction is committed.
weak_identity_map
- When set to the default value of ``False``, a weak-referencing map is
+ When set to the default value of ``True``, a weak-referencing map is
used; instances which are not externally referenced will be garbage
collected immediately. For dereferenced instances which have pending
changes present, the attribute management system will create a temporary
strong-reference to the object which lasts until the changes are flushed
to the database, at which point it's again dereferenced. Alternatively,
- when using the value ``True``, the identity map uses a regular Python
+ when using the value ``False``, the identity map uses a regular Python
dictionary to store instances. The session will maintain all instances
present until they are removed using expunge(), clear(), or purge().