Re:

From: "Merlin Moncure" <merlin(dot)moncure(at)rcsonline(dot)com>
To: "Magnus Hagander" <mha(at)sollentuna(dot)net>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re:
Date: 2005-02-16 13:42:12
Message-ID: 6EE64EF3AB31D5448D0007DD34EEB3412A7624@Herge.rcsinc.local
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

> Question 1: Is your writeback cache really disabled in Linux, on the
> harddrive? Windows fsync will *write through the disk write cache* if
> the driver is properly implemented. AFAIK, on Linux if write cache is
> enabled on the drive, fsync will only get into the cache.
> 800tps sounds unreasonably high on a notebook.
>
> Question 2: Please try disabling the stats connector and see if that
> helps. Merlin Moncure reported some scalability issues with the stats
> collector previously.
>
>
> > Several yeas ago (about 1997-1998) Oleg Bartunov and me had
> > the same performance results (Linux vs Windows NT + cygwin).
> > It was the discussion at this list with resume that the
> > reason is the implementation of shared memory under Windows.
> > Every IPC operation results the HDD access.
>
> It shouldn't in 8.0 - at least not on the native win32. Don't know
about
> cygwin.

The price on win32 for row level stats collector is fairly high. Also
the stats collector resets randomly under very high loads. However I
don't think this is what's going on here.

Also, IPC is out. The win32 IPC implementation is fine, if somewhat
slower than linux implementation. It's all about syncing, IMO.

Merlin

Browse pgsql-hackers by date

  From Date Subject
Next Message pgsql 2005-02-16 14:39:09 Re: Help me recovering data
Previous Message Magnus Hagander 2005-02-16 12:05:03 Re: