mattermost 6.4.0 upgrade
upgrade stuck on this:
mysql> show full processlist;
+------+------------------+-----------+------------+---------+------+-------------------+----------------------------------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+------+------------------+-----------+------------+---------+------+-------------------+----------------------------------------------------------------------------------------------+
| 5787 | mattermost | localhost | mattermost | Query | 1382 | copy to tmp table | ALTER TABLE Posts MODIFY COLUMN FileIds text, MODIFY COLUMN Props JSON, DROP COLUMN ParentId |
+------+------------------+-----------+------------+---------+------+-------------------+----------------------------------------------------------------------------------------------+