directly into the unit of work's facility for emitting INSERT
and UPDATE statements has been created.  When used correctly,
this expert-oriented system can allow ORM-mappings to be used
to generate bulk insert and update statements batched into
executemany groups, allowing the statements to proceed at
speeds that rival direct use of the Core.
fixes #3100

- start writing docs

to the aliasing syntax, as well as a new CTE feature
:meth:`.CTE.suffix_with`, which is useful for adding in special
Oracle-specific directives to the CTE.
fixes #3220

improved in conjunction with loader directives such as
:func:`.joinedload` and :func:`.contains_eager` such that if
two :meth:`.PropComparator.of_type` modifiers of the same
base type/path are encountered, they will be joined together
into a single "polymorphic" entity, rather than replacing
the entity of type A with the one of type B.  E.g.
a joinedload of ``A.b.of_type(BSub1)->BSub1.c`` combined with
joinedload of ``A.b.of_type(BSub2)->BSub2.c`` will create a
single joinedload of ``A.b.of_type((BSub1, BSub2)) -> BSub1.c, BSub2.c``,
without the need for the ``with_polymorphic`` to be explicit
in the query.
fixes #3256

issues