From: Tsunakawa, Takayuki/綱川 貴之 <tsunakawa.ta...@fujitsu.com> Sent: Friday, May 28, 2021 8:55 AM > To: 'Bharath Rupireddy' <bharath.rupireddyforpostg...@gmail.com>; Hou, > Zhijie/侯 志杰 <houzj.f...@fujitsu.com> > Cc: Amit Kapila <amit.kapil...@gmail.com>; Tang, Haiying/唐 海英 > <tanghy.f...@fujitsu.com>; PostgreSQL-development > <pgsql-hack...@postgresql.org>; Zhihong Yu <z...@yugabyte.com>; Luc > Vlaming <l...@swarm64.com>; Dilip Kumar <dilipbal...@gmail.com>; > vignesh C <vignes...@gmail.com> > Subject: RE: Parallel Inserts in CREATE TABLE AS > > From: Bharath Rupireddy <bharath.rupireddyforpostg...@gmail.com> > > I'm still not sure why the execution time with 0 workers (or serial > > execution or no parallelism involved) on my testing system is 112 sec > > compared to 58 sec on Hou-San's system for the same use case. Maybe > > the testing system I'm using is not of the latest configuration compared to > others. > > What's the setting of wal_level on your two's systems? I thought it could be > that you set it to > minimal, while Hou-san set it to minimal. (I forgot the > results of 2 and 4 workers, though.)
I think I followed the configuration that Bharath-san mentioned. It could be the hardware's difference, because I am not using SSD. I will try to test on SSD to see if there is some difference. I only change the the following configuration: shared_buffers = 40GB max_worker_processes = 32 max_parallel_maintenance_workers = 24 max_parallel_workers = 32 synchronous_commit = off checkpoint_timeout = 1d max_wal_size = 24GB min_wal_size = 15GB autovacuum = off Best regards, houzj
