Re: Libpq is very slow on windows but fast on linux.

On 11/06/10 5:12 PM, Rob Brown-Bayliss wrote:
> On Sun, Nov 7, 2010 at 1:06 PM, John R Pierce<pierce@hogranch.com>  wrote:
>> I think I'd run a packet sniffer like Wireshark on both client platforms,
>> sniffing 5432/tcp and see if there's something unusual in the timing of the
>> packets, incorrect MTU or something, lost packets and extra retries, or
>> whatever.   Perhaps Windows isn't using a sufficiently large TCP Recieve
>> Window (RWIN) value, or something.
> I am a bit out of my depth there, but for all other network use the
> machine seems the same in either os.  That is no noticiable difference
> in download/upload speed.

download/uploads from/to this same server in Canada ?

Wireshark is pretty easy to use.   tell it you only want to capture TCP
traffic on port 5432 (to or from 5432), then start its capture and run
your query.   it shows the network packets with a ton of info including
a millisecond accurate timestamp on each packet.   do this on each OS
and compare the timings on these captures (you can save the capture from
one system and load it on wireshark on the other OS so you can do side
by side compares)

studying the details of a TCP connection via Wireshark should lead to a
good deal of understanding of the underpinnings of TCP/IP networking.