Re: Synchronous writes & TEMP

Jonathan,

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:c83o56$qf5$1_at_hercules.btinternet.com...
>
> Note inline
>
> --
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk
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> "Frank van Bortel" <fvanbortel_at_netscape.net> wrote in message
> news:c838er$fsc$1_at_news1.tilbu1.nb.home.nl...
> > VC wrote:
> >
> >
> > I'd say Karsten had a plausible explanation: the process
> > that needs temp to be written has nothing better to do
> > than wait - so why bother with an extra communications
> > process and async writes when there's a synchronous write,
> > that will only return when done?
> >
>
> I think the point that VC is making is that when you
> open a file with ODSYNC, a call from the end-user
> process blocks until the write is on the disk. However,
> if the file is not opened with ODSYNC, then the
> end-user process will be notified as soon as the
> write has reached the file-system buffer.
>
> Since a "sort to disk" could (presumably) re-read from
> the file-system buffer, even when the data had not
> yet reached the disc, and could benefit from faster
> performance if it did so, it seems pointless to insist
> that a write to TEMP should be forced to disc.

Precisely.

Now, the original question remains: why does Oracle use synchronous (also known as 'delayed') writes ?

Regards.

VC
>
>
Received on Fri May 14 2004 - 21:23:08 CDT