On Sat, Jun 16, 2018 at 9:38 PM, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > On 06/15/2018 08:01 PM, Andres Freund wrote: >> On 2018-06-14 10:13:44 +0300, Konstantin Knizhnik wrote: >>> On 14.06.2018 09:52, Thomas Munro wrote: >>>> Why stop at the page cache... what about shared buffers? >>> >>> It is good question. I thought a lot about prefetching directly to shared >>> buffers. >> >> I think that's definitely how this should work. I'm pretty strongly >> opposed to a prefetching implementation that doesn't read into s_b. > > Could you elaborate why prefetching into s_b is so much better (I'm sure it > has advantages, but I suppose prefetching into page cache would be much > easier to implement).
posix_fadvise(POSIX_FADV_WILLNEED) might already get most of the speed-up available here in the short term for this immediate application, but in the long term a shared buffers prefetch system is one of the components we'll need to support direct IO. -- Thomas Munro http://www.enterprisedb.com
