- update to 1.4.41:
* Fixed issue where use of the :func:`_sql.table` construct, passing a string
for the :paramref:`_sql.table.schema` parameter, would fail to take the
"schema" string into account when producing a cache key, thus leading to
caching collisions if multiple, same-named :func:`_sql.table` constructs
with different schemas were used.
* Fixed event listening issue where event listeners added to a superclass
would be lost if a subclass were created which then had its own listeners
associated. The practical example is that of the :class:`.sessionmaker`
class created after events have been associated with the
:class:`_orm.Session` class.
* Hardened the cache key strategy for the :func:`_orm.aliased` and
:func:`_orm.with_polymorphic` constructs. While no issue involving actual
statements being cached can easily be demonstrated (if at all), these two
constructs were not including enough of what makes them unique in their
cache keys for caching on the aliased construct alone to be accurate.
* Fixed regression appearing in the 1.4 series where a joined-inheritance
query placed as a subquery within an enclosing query for that same entity
would fail to render the JOIN correctly for the inner query. The issue
manifested in two different ways prior and subsequent to version 1.4.18
(related issue :ticket:`6595`), in one case rendering JOIN twice, in the
other losing the JOIN entirely. To resolve, the conditions under which
"polymorphic loading" are applied have been scaled back to not be invoked
for simple joined inheritance queries.
* Fixed issue in :mod:`sqlalchemy.ext.mutable` extension where collection
links to the parent object would be lost if the object were merged with
:meth:`.Session.merge` while also passing :paramref:`.Session.merge.load`
as False.
* Fixed issue involving :func:`_orm.with_loader_criteria` where a closure
variable used as bound parameter value within the lambda would not carry