consistently maintained. The FAQ section :ref:`faq_session_rollback` contains a
more detailed description of this behavior.
+.. _session_get:
+
+Get by Primary Key
+------------------
+
+As the :class:`_orm.Session` makes use of an :term:`identity map` which refers
+to current in-memory objects by primary key, the :meth:`_orm.Session.get`
+method is provided as a means of locating objects by primary key, first
+looking within the current identity map and then querying the database
+for non present values. Such as, to locate a ``User`` entity with primary key
+identity ``(5, )``::
+
+ my_user = session.get(User, 5)
+
+The :meth:`_orm.Session.get` also includes calling forms for composite primary
+key values, which may be passed as tuples or dictionaries, as well as
+additional parameters which allow for specific loader and execution options.
+See :meth:`_orm.Session.get` for the complete parameter list.
+
+.. seealso::
+
+ :meth:`_orm.Session.get`
+
.. _session_expiring:
Expiring / Refreshing
..
-* **the populate_existing() method** - this method is actually on the
- :class:`_orm.Query` object as :meth:`_orm.Query.populate_existing`
- and indicates that it should return objects that are unconditionally
+* **the populate_existing() method or execution option** - This is now
+ an execution option documented at :ref:`orm_queryguide_populate_existing`; in
+ legacy form it's found on the :class:`_orm.Query` object as the
+ :meth:`_orm.Query.populate_existing` method. This operation in either form
+ indicates that objects being returned from a query should be unconditionally
re-populated from their contents in the database::
u2 = session.query(User).populate_existing().filter(id=5).first()
INSERT many rows at once while still being able to retrieve the primary key
values.
-Identity Map
-^^^^^^^^^^^^
+Getting Objects by Primary Key from the Identity Map
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The primary key identity of the objects are significant to the :class:`_orm.Session`,
as the objects are now linked to this identity in memory using a feature