``cascade="all, delete-orphan"`` automatically on a one-to-many
relationship/backref where the foreign key is detected as containing
one or more non-nullable columns.  This argument is present in the
keywords passed to :func:`.automap.generate_relationship` in this
case and can still be overridden.  Additionally, if the
:class:`.ForeignKeyConstraint` specifies ``ondelete="CASCADE"``
for a non-nullable or ``ondelete="SET NULL"`` for a nullable set
of columns, the argument ``passive_deletes=True`` is also added to the
relationship.  Note that not all backends support reflection of
ondelete, but backends that do include Postgresql and MySQL.
fixes #3210

as that of :ticket:`3199`, when the ``named=True`` parameter
would be used.  Some events would fail to register, and others
would not invoke the event arguments correctly, generally in the
case of when an event was "wrapped" for adaption in some other way.
The "named" mechanics have been rearranged to not interfere with
the argument signature expected by internal wrapper functions.
fixes #3197

setups, where the attempt to check for "duplicate class name" in
declarative would hit upon a not-totally-cleaned-up weak reference
related to some other class being removed; the check here now ensures
the weakref still references an object before calling upon it further.
fixes #3208

ORM events but also engine events, where the usual logic of
"de duplicating" a redundant call to :func:`.event.listen`
with the same arguments would fail, for those events where the
listener function is wrapped.  An assertion would be hit within
registry.py.  This assertion has now been integrated into the
deduplication check, with the added bonus of a simpler means
of checking deduplication across the board.
fixes #3199

method :meth:`.Query.with_statement_hint` to support statement-level
hints that are not specific to a table.
fixes #3206

kept separate from Postgresql's ON COMMIT for now even though ON COMMIT
is in the SQL standard; the option is still very specific to temp tables
and we eventually would provide a more first class temporary table
feature.
- oracle can apparently do get_temp_table_names() too, so implement that,
fix its get_table_names(), and add it to #3204.  fixes #3204 again.

:meth:`.Inspector.get_temp_view_names`; currently, only the
SQLite dialect supports these methods.    The return of temporary
table and view names has been **removed** from SQLite's version
of :meth:`.Inspector.get_table_names` and
:meth:`.Inspector.get_view_names`; other database backends cannot
support this information (such as MySQL), and the scope of operation
is different in that the tables can be local to a session and
typically aren't supported in remote schemas.
fixes #3204