I'll need to write up how the scheduler works at some point, but it's heavily based on these papers[0][1]. It solves two different problems. First, it lets us throttle resource-intensive queries. Second, it enables work stealing. If you have idle cores on your machine, we'll assign those cores to running queries to help speed them up. That means if you have an over-provisioned machine, we'll make use of the extra capacity to speed your queries up.

[0] https://15721.courses.cs.cmu.edu/spring2016/papers/p743-leis...

[1] https://db.in.tum.de/~kohn/papers/query-scheduling-sigmod21....