Re: SCSI vs. IDE performance test

Rick Gigger <rick@alpinenetworking.com>

From: "Rick Gigger" <rick@alpinenetworking.com>
To: <pgsql-general@postgresql.org>
Date: 2003-10-28T21:51:10Z
Lists: pgsql-general
> "Rick Gigger" <rick@alpinenetworking.com> writes:
> >> "we have no portable means of expressing that exact constraint to the
> >> kernel"
> > Does this mean that specific operating systems have a better way of
dealing
> > with this?  Which ones and how?
>
> I'm not aware of any that offer a way of expressing "write these
> particular blocks before those particular blocks".  It doesn't seem like
> it would require rocket scientists to devise such an API, but no one's
> got round to it yet.  Part of the problem is that the issue would have
> to be approached at multiple levels: there is no point in offering an
> OS-level API for this when the hardware underlying the bus-level API
> (IDE) is doing its level best to sabotage the entire semantics.

But for those of us using scsi wouldn't it be possible to get a performance
gain here?  Would the gain be worth the effort?