Re: Allowing WAL fsync to be done via O_SYNC

Bruce Momjian <pgman@candle.pha.pa.us>

From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Alfred Perlstein <bright@wintelcom.net>
Cc: "William K. Volkman" <wkv@hiscorp.net>, pgsql-hackers@postgresql.org
Date: 2001-03-19T14:29:01Z
Lists: pgsql-hackers
> * William K. Volkman <wkv@hiscorp.net> [010318 11:56] wrote:
> > The Hermit Hacker wrote:
> > >> 
> > > But, with shared libraries, are you really pulling in a "whole
> > > thread-support library"?  My understanding of shared libraries (altho it
> > > may be totally off) was that instead of pulling in a whole library, you
> > > pulled in the bits that you needed, pretty much as you needed them ...
> > 
> > Just by making a thread call libc changes personality to use thread
> > safe routines (I.E. add mutex locking).  Use one thread feature, get
> > the whole set...which may not be that bad.
> 
> Actually it can be pretty bad.  Locked bus cycles needed for mutex
> operations are very, very expensive, not something you want to do
> unless you really really need to do it.

And don't forget buggy implementations.

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