We're trying to improve performance for RecentChanges queries involving ORES (see parent task, as well as others). One of the thing we think might help is to add an index on (oresc_rev, oresc_probability).
However, we're not sure. Do you think it would be better to do it on a test replica, or do it in production and proceed from there?
We would like to test on a replica of large recentchanges tables (in particular enwiki and ruwiki), preferably on machines with performance similar to production.