On 2018-09-03 14:56:28 -0400, Bruce Momjian wrote: > On Mon, Sep 3, 2018 at 11:42:31AM -0700, Andres Freund wrote: > > > and JIT, so it doesn't have to be 100% accurate. > > > > JIT decision is done after main planning, so we know the cost. > > Well, as I remember, we are considering disabling JIT in PG 11 because > of the use of fixed costs to trigger it. Could executor information > help decide to use JIT?
I don't think so. The issues with JIT planning are more that it's costing is simplistic (for good-ish reason, to avoid increasing the number of plans), and that there's no caching (lots of infrastructure work needed). Greetings, Andres Freund
