Slava @ RethinkDB here. The challenge with database systems is that essentially they're complete runtimes -- the user can send a huge variety of queries which

Slava @ RethinkDB here. The challenge with database systems is that essentially they're complete runtimes -- the user can send a huge variety of queries which are programs that need to be executed by the runtime. So there is no way to fix performance once and for all -- it's a continuous process that never stops. We've worked out a lot of performance issues since then, and keep working on them every day. For anyone reading this, if there is a particular workload that's slow, please let us know and we'll work to prioritize it ASAP.