Comment 6 for bug 1769897

Reviewed: https://review.openstack.org/567593
Committed: https://git.openstack.org/cgit/openstack/ovsdbapp/commit/?id=fd64d41ea6f208a5752fbcd45952a04633ee1392
Submitter: Zuul
Branch: stable/queens

commit fd64d41ea6f208a5752fbcd45952a04633ee1392
Author: Daniel Alvarez <email address hidden>
Date: Tue May 8 16:02:56 2018 +0200

    Improve DbListCommand operation from O(n^2) to O(n)

    Right now the DbListCommand retrieves the uuid's of all the elements
    passed in as argument. This is an O(n^2) operation so when the number
    of elements in a grows it's likely that we get Timeout Exceptions.

    Instead of doing this, whenever possible, we'll retrieve all the
    elements (from the in-memory replica) and only fetch those who were
    passed as arguments avoiding the O(n^2) operation.

    (cherry picked from 476b174f7d303c501fa2f3b91efda659ed9b9f3d)
    Change-Id: I71411e5dd68753eb3825f8b0e91009f87de1b260
    Closes-Bug: #1769897