Re: insert performance for win32 - Mailing list pgsql-performance

From Tom Lane
Subject Re: insert performance for win32
Date
Msg-id 7860.1131062219@sss.pgh.pa.us
Whole thread Raw
In response to Re: insert performance for win32  ("Merlin Moncure" <merlin.moncure@rcsonline.com>)
Responses Re: insert performance for win32
List pgsql-performance
"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
> ok, I generated a test case which was 250k inserts to simple two column
> table all in single transaction.  Every 50k inserts, time is recorded
> via timeofday().

You mean something like the attached?

> Running from remote, Time progression is:
> First  50k: 20 sec
> Second    : 29 sec
> [...]
> final:    : 66 sec

On Unix I get a dead flat line (within measurement noise), both local
loopback and across my LAN.

after 50000 30.20 sec
after 100000 31.67 sec
after 150000 30.98 sec
after 200000 29.64 sec
after 250000 29.83 sec

"top" shows nearly constant CPU usage over the run, too.  With a local
connection it's pretty well pegged, with LAN connection the server's
about 20% idle and the client about 90% (client machine is much faster
than server which may affect this, but I'm too lazy to try it in the
other direction).

I think it's highly likely that you are looking at some strange behavior
of the Windows TCP stack.

            regards, tom lane


Attachment

pgsql-performance by date:

Previous
From: "Merlin Moncure"
Date:
Subject: Re: insert performance for win32
Next
From: Qingqing Zhou
Date:
Subject: Re: insert performance for win32