On 11/29/22 03:36, Alvaro Herrera
wrote:
On 2022-Nov-28, Mladen Gogala wrote:As for JIT, I've recently asked that question myself. I was told that PostgreSQL with LLVM enabled performs approximately 25% better than without it.Hmm, actually, normally you're better off turning JIT off, because it's very common to diagnose cases of queries that become much, much slower because of it. Some queries do become faster, but it's not a wide margin, and it's not a lot. There are rare cases where JIT is beneficial, but those tend to be queries that take upwards of several seconds already. IMO it was a mistake to turn JIT on in the default config, so that's one thing you'll likely want to change.
Hmmm, I think I will run pgbench with and without JIT on and see
the difference.
-- Mladen Gogala Database Consultant Tel: (347) 321-1217 https://dbwhisperer.wordpress.com
