is the flag that per :ticket:`2992` causes an order by or group by
an expression that's also in the columns clause to be copied by
label, even if referenced as the expression object.   The behavior
for MSSQL is now the old behavior that copies the whole expression
in by default, as MSSQL can be picky on these particularly in
GROUP BY expressions.
fixes #3338
- Add a test that includes a composed label in a GROUP BY

That is, after exhausing all rows using the fetch methods, the
DBAPI cursor is released as before and the object may be safely
discarded, but the fetch methods may continue to be called for which
they will return an end-of-result object (None for fetchone, empty list
for fetchmany and fetchall).   Only if :meth:`.ResultProxy.close`
is called explicitly will these methods raise the "result is closed"
error.
fixes #3330 fixes #3329

``pg_catalog.pg_table_is_visible(c.oid)``, rather than testing
for an exact schema match, when the schema name is None; this
so that the method will also illustrate that temporary tables
are present.  Note that this is a behavioral change, as Postgresql
allows a non-temporary table to silently overwrite an existing
temporary table of the same name, so this changes the behavior
of ``checkfirst`` in that unusual scenario.
fixes #3264

name, this is sort of a bug for oracle

defaults if otherwise unspecified; the limitation where non-
server column defaults aren't included in an INSERT FROM
SELECT is now lifted and these expressions are rendered as
constants into the SELECT statement.

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.