Comment 8 for bug 1280055

Reviewed: https://review.openstack.org/79070
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=1a8dd2487d95327b97ebf8e8b4a27420d1432fd4
Submitter: Jenkins
Branch: master

commit 1a8dd2487d95327b97ebf8e8b4a27420d1432fd4
Author: Matt Riedemann <email address hidden>
Date: Fri Mar 7 06:29:38 2014 -0800

    Remove duplicate code from nova.db.sqlalchemy.utils

    There is a lot of code in nova.db.sqlalchemy.utils which is also in
    oslo-incubator's openstack.common.db.sqlalchemy.utils module so this
    patch goes through and cleans up Nova.

    Notable differences:

    1. modify_indexes was nova-only but no longer used after the migration
       compaction work, so it's just removed here. It also didn't really
       work for mysql in cases where the index name was too long so it
       could be table-specific and therefore unusable in some mysql cases.
       See commit 029ebab for history.
    2. create_shadow_table was not in oslo-incubator and it's also not
       currently used in nova after the migration compaction, however,
       I leave it here in case future migrations in Nova need to use it.
       This patch does replace the usage of _get_not_supported_column in
       create_shadow_table to use the same method from oslo's DB utils.
    3. DeleteFromSelect is still used within nova.db.api per
       commit b36826e so we could move it to oslo-incubator but this
       patch leaves it for now since it's only used in Nova.
    4. InsertFromSelect was introduced with commit 2e403b2 but now there
       is a copy in oslo-incubator so we can remove our usage in nova.
       However, oslo doesn't have the unit test that nova does, so the
       unit test has been moved to oslo with change I457acf33.
    5. Oslo has is_backend_avail and get_connect_string methods so use
       those in test_migrations.py while doing this update.

    Closes-Bug: #1280055

    Change-Id: Iefa5b4311f1fe1a5da31cf527521c393f2face7c