On Wed, Jan 15, 2014 at 2:52 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> I think that the bottom line is that we're not likely to make massive >> changes to the way that we do block caching now. Even if some other >> scheme could work much better on Linux (and so far I'm unconvinced >> that any of the proposals made here would in fact work much better), >> we aim to be portable to Windows as well as other UNIX-like systems >> (BSD, Solaris, etc.). So using completely Linux-specific technology >> in an overhaul of our block cache seems to me to have no future. > > Unfortunately, I have to agree with this. Even if there were a way to > merge our internal buffers with the kernel's, it would surely be far > too invasive to coexist with buffer management that'd still work on > more traditional platforms. > > But we could add hint calls, or modify the I/O calls we use, and that > ought to be a reasonably localized change.
That's what's pretty nice with the zero-copy read idea. It's almost transparent. You read to a page-aligned address, and it works. The only code change would be enabling zero-copy reads, which I'm not sure will be low-overhead enough to leave enabled by default. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers