Josh Berkus wrote: > On 11/20/10 6:11 PM, Jeff Janes wrote: >> True, but I think that changing these from their defaults is not >> considered to be a dark art reserved for kernel hackers, i.e they are >> something that sysadmins are expected to tweak to suite their work >> load, just like the shmmax and such. > > I disagree. Linux kernel hackers know about these kinds of parameters, > and I suppose that Linux performance experts do. But very few > sysadmins, in my experience, have any idea.
To me, a lot of this conversation feels parallel to the arguments the occasionally come up debating writing directly to raw disks bypassing the filesystems altogether. Might smoother checkpoints be better solved by talking to the OS vendors & virtual-memory-tunning-knob-authors to work with them on exposing the ideal knobs; rather than saying that our only tool is a hammer(fsync) so the problem must be handled as a nail. Hypothetically - what would the ideal knobs be? Something like madvise WONTNEED but that leaves pages in the OS's cache after writing them? -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
