the memory tests are solely responsible for the largest chunk of
time and CPU energy taken up in running the tests.   Regressions
in this area are nonexistent unless major changes are being
taken up.   Try to revert them to False and see if a single
gerrit job can perhaps run these.

Change-Id: Ibaead2d1c0a76f1339bee63652a8aead689e8b75

We want to use Oracle version >=7 for all platforms,
but <8 for Python 2.

Similarly, we want to use mysqlclient >= 1.4.0 for all
platforms, but < 2 for Python 2.

Have tox.ini defer to setup.cfg for DBAPIs.

We're not testing mysql-connector-python right now so remove
this from tox.ini.

Change-Id: I02611937da71d2950545e42c34f0b9798478e2a8

The psycopg2 dialect now defaults to using the very performant
``execute_values()`` psycopg2 extension for compiled INSERT statements,
and also impements RETURNING support when this extension is used.  This
allows INSERT statements that even include an autoincremented SERIAL
or IDENTITY value to run very fast while still being able to return the
newly generated primary key values.   The ORM will then integrate this
new feature in a separate change.

Implements RETURNING for insert with executemany

Adds support to return_defaults() mode and inserted_primary_key
to support mutiple INSERTed rows, via return_defauls_rows
and inserted_primary_key_rows accessors.

within default execution context, new cached compiler
getters are used to fetch primary keys from rows

inserted_primary_key now returns a plain tuple. this
is not yet a row-like object however this can be
added.

Adds distinct "values_only" and "batch" modes, as
"values" has a lot of benefits but "batch" breaks
cursor.rowcount

psycopg2 minimum version 2.7 so we can remove the
large number of checks for very old versions of
psycopg2

simplify tests to no longer distinguish between
native and non-native json

Fixes: #5401
Change-Id: Ic08fd3423d4c5d16ca50994460c0c234868bd61c

we want to be able to specify --output-file

Change-Id: Ib4e992d47587385a50c35ca915bc5adcb2ca49fa

Trying the pr to check if it works right away

### Description
<!-- Describe your changes in detail -->

### Checklist
<!-- go over following points. check them with an `x` if they do apply, (they turn into clickable checkboxes once the PR is submitted, so no need to do everything at once)

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This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [x] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #5222
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5222
Pull-request-sha: afbb8567525f3841554d3ba599ef4d713c78e647

Change-Id: I4981b02f900e76e446cf42e6cc6495ffc0883951

1. ensure provision.py loads dialect implementations when running
reap_dbs.py.   Reapers haven't been working since
598f2f7e557073f29563d4d567f43931fc03013f .

2. add some exclusion rules to allow the sqlite_file target to work;
add to tox.

3. add reap dbs target for SQLite, repair SQLite drop_db routine
which also wasn't doing the right thing for memory databases
etc.

4. Fix logging in provision files, as the main provision logger
is the one that's enabled by reap_dbs and maybe others, have all
the provision files use the provision logger.

Fixes: #5180
Fixes: #5168

Change-Id: Ibc1b0106394d20f5bcf847f37b09d185f26ac9b5

We need no tests to run for sqlite_file until we merge
a full fix for it.   We'd like Jenkins to include this target.

Change-Id: I2737fa462572f08e2925b232a8f24d1ecd26b3ac

So that we can enable this in jenkins until
 Ibc1b0106394d20f5bcf847f37b09d185f26ac9b5 is merged.

Change-Id: Ia704e75bf3767e02d448a6af02530dfc89c9920b

Change-Id: I3b86bb3b4263048646676972bb2a870c7e2a7393

cx_Oracle is dropping Python 2 in version 8.0
mysqlclient is dropping Python 2 in version 2.0

We are no longer testing cx_Oracle < 7 on CI so drop older
cx_Oracle versions from tox.

Change-Id: I18d8b47077d50ac02aedb6fdeb24f7c99b56aa7c