Comment 12 for bug 1582585

Reviewed: https://review.openstack.org/339294
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=f534f36246fd0b41bcdc2a664369507f9e299266
Submitter: Jenkins
Branch: master

commit f534f36246fd0b41bcdc2a664369507f9e299266
Author: Boris Bobrov <email address hidden>
Date: Fri Jul 8 02:49:03 2016 +0300

    Faster id mapping lookup

    id_mapping_api was designed to make a query per entity to fetch
    public ids. This lead to a very poor performance when there were many
    entries in LDAP. For example, for 15k entries 15k MySQL queries were
    required. For the first run 15k INSERTs were required, which makes
    things even worse.

    Change this behavior to fetch related mappings from MySQL as a list and
    perform the necessary join in-memory.

    bp ldap-preprocessing
    Partial-Bug: 1582585
    Change-Id: I2c266e91f2f05be760f8a3eea3738868243cc9c6