We don't use the https://orientdb.com/docs/2.2.x/Live-Query.html feature and disabling it completely (ie. removing it totally as a DB hook) will give a small performance boost.
It will also guarantee to remove future log-spam issues caused by OLiveQueryHook's erroneous assumption that there will be a valid DB thread-local when it's called - which isn't always the case depending on the scenario.
This has led in the past to a number of log-spam reports, mostly on HA but also on a couple of non-HA systems under stress. The previous reports should have been fixed now by upstream changes, but disabling the live-query feature would protect us from similar issues in the future.