postgresql13-llvm jit-13.5-1PGDG.rhel8.x86_64

Mladen Gogala <gogala.mladen@gmail.com>

From: Mladen Gogala <gogala.mladen@gmail.com>
To: pgsql-performance@lists.postgresql.org
Date: 2021-11-15T04:21:54Z
Lists: pgsql-performance
I was trying to upgrade my test 13.4 instance on Oracle Linux 8.4 
(x86_64) to 13.5. I can't upgrade postgresql13-llvm jit because Oracle's 
and Red Hat repositories still don't have the required version of llvm 
(12.1.0.2):

root@postgres mgogala]# rpm -qa|grep llvm
llvm-libs-11.0.1-2.0.1.module+el8.4.0+20397+f876858a.x86_64
llvm7.0-libs-7.0.1-7.el8.x86_64
llvm-test-11.0.1-2.0.1.module+el8.4.0+20397+f876858a.x86_64
llvm-11.0.1-2.0.1.module+el8.4.0+20397+f876858a.x86_64
llvm-static-11.0.1-2.0.1.module+el8.4.0+20397+f876858a.x86_64
llvm-devel-11.0.1-2.0.1.module+el8.4.0+20397+f876858a.x86_64
[root@postgres mgogala]#

I am getting the following error:

postgresql13-llvm jit-13.5-1PGDG.rhel8.x86_64 requires 
libLLVM-12.so()(64bit), but none of the providers can be installed.

There is a CentOS8-stream version which solves the problem but I cannot 
use that in the office. I will probably have to wait for another month 
before OL8 has everything that I need in its repositories. Now, the 
question is what kind of an impact will running without llvm-jit have? 
According to the links below, llvm-jit effects are quite spectacular:

https://llvm.org/devmtg/2016-09/slides/Melnik-PostgreSQLLLVM.pdf

https://www.pgcon.org/2017/schedule/events/1092.en.html

Now, the question is whether anyone on this list can quantify the 
difference? What would be a better option? To wait for the repos to 
receive the necessary packages or to run without llvm-jit? In the office 
I have some rather large databases and CREATE INDEX CONCURRENTLY and 
REINDEX CONCURRENTLY  fixes in 13.5 are highly desired but not at the 
cost of the overall application performance.

Regards


-- 
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com