Skip site navigation (1) Skip section navigation (2)

Re: [PATCHES] SRA Win32 sync() code

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL-patches <pgsql-patches(at)postgresql(dot)org>,PostgreSQL Win32 port list <pgsql-hackers-win32(at)postgresql(dot)org>
Subject: Re: [PATCHES] SRA Win32 sync() code
Date: 2003-11-16 18:06:48
Message-ID: 200311161806.hAGI6mu11492@candle.pha.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-hackers-win32pgsql-patches
Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > Tom Lane wrote:
> >> One reason I like the idea of adopting a sync-when-you-write policy is
> >> that it eliminates the need for anything as messy as that.
> 
> > Yes, but can we do it without causing a performance degredation, and I
> > would hate to change something to make things easier on Win32 while
> > penalizing all platforms.
> 
> Having to keep a list of modified files in shared memory isn't a penalty?
> 
> Seriously though, if we can move the bulk of the writing work into
> background processes then I don't believe that there will be any
> significant penalty for regular backends.  And I believe that it would
> be a huge advantage from a correctness point of view if we could stop
> depending on sync().  The fact that Windows hasn't got sync() is merely
> another reason we should stop using it.

If the background writer starts using fsync(), we can have normal
backends that do a write() set a shared memory boolean.  We can then
test that boolean and do sync() only if other backends had to do their
own writes.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

In response to

Responses

pgsql-hackers by date

Next:From: Tom LaneDate: 2003-11-16 18:15:27
Subject: Re: interesting SIGNAL 10 (BUSERR) on CVS
Previous:From: Larry RosenmanDate: 2003-11-16 18:01:35
Subject: Re: interesting SIGNAL 10 (BUSERR) on CVS

pgsql-patches by date

Next:From: Manfred SpraulDate: 2003-11-16 18:20:14
Subject: Re: SIGPIPE handling
Previous:From: Bruce MomjianDate: 2003-11-16 18:03:25
Subject: Re: SIGPIPE handling

pgsql-hackers-win32 by date

Next:From: Tom LaneDate: 2003-11-16 18:21:38
Subject: Re: [PATCHES] SRA Win32 sync() code
Previous:From: Andrew DunstanDate: 2003-11-16 17:38:52
Subject: Re: [PATCHES] SRA Win32 sync() code

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group