On Fri, Jan 5, 2018 at 6:28 AM, Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Jan 2, 2018 at 5:23 PM, Andres Freund <and...@anarazel.de> wrote: >> Note that real-world scenarios probably will see somewhat smaller >> impact, as this was measured over a loopback unix sockets which'll have >> smaller overhead itself than proper TCP sockets + actual network. > > What about scenarios with longer-running queries? > > Is it feasible to think about reducing the number of system calls we > issue in cases that weren't previously worth optimizing?
Maybe the places where syscall rate is controlled by arbitrary buffer sizes? Examples: 8kB BufFile buffers and 128kB replication stream buffers. Just an idea, not sure if it's worth looking into; maybe we already spend enough time filling those buffers that a 50% syscall markup won't hurt. -- Thomas Munro http://www.enterprisedb.com
