On Tue, Feb 22, 2022 at 04:12:15PM -0500, Greg Stark wrote: > I've been playing with an idea I had a while back. Basically that it > would be useful to have some "noop" operators that are used purely to > influence the planner. > > For context I've suggested in the past that there are two categories of hints: > > 1 Hints that override the planner's decisions with explicit planning > decisions. These we don't like for a variety of reasons, notably > because users don't have very good knowledge of all the plan types > available and new plan types come out in the future. > > 2 Hints that just influence the estimates that the planner uses to > make its decisions. These seem more acceptable as it amounts to > admitting the users know the distribution of their data and the > behaviour of their functions better than the statistics. Also, there > are plenty of cases where the statistics are really just wild guesses. > They still allow the planner to make decisions about what join orders > or types and so on given the updated data.
#2 is an interesting distinction. -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com If only the physical world exists, free will is an illusion.
