On 12/11/06, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Yeah, that's what I couldn't think of the other day. The principal report was here: http://archives.postgresql.org/pgsql-general/2005-01/msg01231.php By default, Windows XP installs the QoS Packet Scheduler service. It is not installed by default on Windows 2000. After I installed QoS Packet Scheduler on the Windows 2000 machine, the latency problem vanished.
I found a QoS-RVPS service (not sure about the last four characters and I'm sitting at my mac at home now...) on one of the WinXP test boxes, started it and immediately lost network connection :-(. Since I have pretty much the same skepticism regarding the usefulness of a QoS packet scheduler to help with a raw-throughput-problem like Lincoln Yeoh in a follow up mail to the above (http://archives.postgresql.org/pgsql-general/2005-01/msg01243.php), I didn't investigate this further. And regarding the TCP_NODELAY hint from Kevin Grittner: if I am not wrong with interpreting fe_connect.c, the libpq already deals with it (fe_connect.c:connectNoDelay). But this made me think about the 'page'-size I use in my blob table... I tested different sizes on linux some time ago and found that 64KB was optimal. But playing with different sizes again revealed that my windows->linux problem seems to be solved if I use _any_ other (reasonable - meaning something between 4K and 512K) power of two ?!? Does this make sense to anyone? Thanks, axel
