``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.

Calls to reflect a table did not create any UniqueConstraint objects.
The reflection core made no calls to get_unique_constraints and as
a result, the sqlite dialect would never reflect any unique constraints.

MySQL transparently converts unique constraints into unique indexes, but
SQLAlchemy would reflect those as an Index object and as a
UniqueConstraint. The reflection core will now deduplicate the unique
constraints.

PostgreSQL would reflect unique constraints as an Index object and as
a UniqueConstraint object. The reflection core will now deduplicate
the unique indexes.

: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