On 2018-01-08 14:38:20 +1300, Thomas Munro wrote: > 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.
Yea, I suspect that won't make a huge difference - copying an 8kb buffer is typically a lot more than the overhead. The big problem for the demonstrated slowness is really that we send a lot of tiny packets back and forth and wait for them, and that's obviously going to be performance sensitive to syscall speed. Pipelining helps a lot, but isn't that generally applicable... TBH, I don't really see that much we can do from our side for readonly OLTP with prepared statements. Greetings, Andres Freund