On 2014-12-29 16:59:05 -0500, Bruce Momjian wrote: > I am glad someone else considers this important.
I do consider it important. I just considered the lwlock scalability more important... > Andres reported the above 2x pgbench difference in February, but no > action was taken as everyone felt there needed to be more performance > testing, but it never happened: FWIW, I have no idea what exactly should be tested there. Right now I think what we should do is to remove the BUFFERALIGN from shmem.c and instead add explicit alignment code in a couple callers (BufferDescriptors/Blocks, proc.c stuff). > $ pgbench --initialize --scale 1 pgbench Scale 1 isn't particularly helpful in benchmarks, not even read only ones. > $ pgbench --protocol prepared --client 16 --jobs 16 --transactions > 100000 --select-only pgbench I'd suspect you're more likely to see differences with a higher client count. Also, I seriously doubt 100k xacts is enough to get stable results - even on my laptop I get 100k+ TPS. I'd suggest using something like -P 1 -T 100 or so. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers