On Mon, Jul 30, 2018 at 3:02 PM, Andres Freund <andres@anarazel.de> wrote:
Hi, On 2018-07-30 13:31:33 -0400, Jeff Janes wrote: > I don't know where the time is going with the as-committed JIT. None of > the JIT-specific timings reported by EXPLAIN (ANALYZE) add up to anything > close to the slow-down I'm seeing. Shouldn't compiling and optimization > time show up there?
As my timings showed, I don't see the slowdown you're reporting. Could you post a few EXPLAIN ANALYZEs?
I don't think you showed any timings where jit_above_cost < query cost < jit_optimize_above_cost, which is where I saw the slow down. (That is also where things naturally land for me using default settings)
I've repeated my test case on a default build (./configure --with-llvm --prefix=....) and default postgresql.conf, using the post-11BETA2 commit 5a71d3e.
I've attached the full test case, and the full output.
Here are the last two executions, with jit=on and jit=off, respectively. Doing it with TIMING OFF doesn't meaningfully change things, nor does increasing shared_buffers beyond the default.