Hi, anyone using postgres 9.3+ with big buffer sizes? (Not sure where big starts) I'm interested how this behaves. As they moved away from SysV shm. First I thought it was bug. Like someone else:
http://www.postgresql.org/message-id/[email protected] But after some digging: https://bucardo.org/postgres_all_versions.html#version_9.3 "Greatly reduce System V shared memory requirements" Source: postgresql-9.3.10/src/backend/port/sysv_shmem.c * As of PostgreSQL 9.3, we normally allocate only a very small amount of * System V shared memory, and only for the purposes of providing an * interlock to protect the data directory. The real shared memory block * is allocated using mmap(). This works around the problem that many * systems have very low limits on the amount of System V shared memory * that can be allocated. Even a limit of a few megabytes will be enough * to run many copies of PostgreSQL without needing to adjust system * settings. On solarish system the shared mem is allocated as ISM. (See bug report above) I kind of wonder what performance impact (except for beeing locked memory with ism) this has and if anyone every tested it. I would think having large pages would be quite a benefit for larger installs. So my guess would be to have postgres use full sysv shm again with ism would be a good thing. Or is mmap good enough these days? I know sdc runs on 9.2 so joyent might hit this if they ever are going to update :) Thoughts, input, tests? :) Greetings Jan ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
