Re: Bgwriter behavior

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
Cc: Gavin Sherry <swm(at)linuxworld(dot)com(dot)au>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Bgwriter behavior
Date: 2004-12-22 05:02:14
Message-ID: 29385.1103691734@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-patches

Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> The only way I could see it being worse than pre-8.0 is that the
> bgwriter is doing fsync of all open files rather than using sync. Other
> than that, I think it should behave the same, or slightly better,
> right?

It's possible that there exist platforms on which this is a loss ---
that is, the OS's handling of fsync is so inefficient that multiple
fsync calls are worse than one sync call even though less I/O is forced.
But I haven't seen any actual evidence of that; and if such platforms
do exist I'm not sure I'd blink anyway. We are not required to optimize
for brain-dead kernels.

regards, tom lane

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Jaime Casanova 2004-12-22 07:52:02 Re: Thoughts about updateable views
Previous Message Bruce Momjian 2004-12-22 04:50:44 Re: Bgwriter behavior

Browse pgsql-patches by date

  From Date Subject
Next Message Euler Taveira de Oliveira 2004-12-22 05:05:09 Re: uptime function to postmaster
Previous Message Alvaro Herrera 2004-12-22 05:00:38 Re: uptime function to postmaster