[TUHS] Re: Perkin-Elmer Sort/Merge II vs Unix sort(1)

[Bakul Shah via TUHS <tuhs@tuhs.org>]

On Jan 18, 2025, at 7:16 AM, Larry McVoy <lm@mcvoy.com> wrote:
> 
> On Sat, Jan 18, 2025 at 04:51:15PM +0200, Diomidis Spinellis wrote:
>> I'm sure the mainframe sort programs did some pretty amazing things and
>> could run circles around the puny 830 line Unix Seventh Edition sort
>> program.  The 215 page IBM DOS VS sort documentation that John Levine posted
>> here is particularly impressive.  But I can't stop thinking that, in common
>> with the mainframes these programs were running on, they represent a mindset
>> that has been surpassed by superior ideas.
> 
> I disagree.  Go back and read the reply where someone was talking about
> sorting datasets that spanned multiple tapes, each of which was much
> larger than local disk.  sort(1) can't begin to think about handling
> something like that.
> 
> I have a lot of respect for how Unix does things, if the problem fits
> then the Unix answer is more simple, more flexible, it's better.  If
> the problem doesn't fit, the Unix answer is awful.
> 
> cmd < data | cmd2 | cmd3
> 
> is a LOT of data copying.  A custom answer that did all of that in
> one address space is a lot more efficient but also a lot more special
> purpose.  Unix wins on flexibility and simplicity, special purpose
> wins on performance.

Mainframes had usage based pricing, not unlike what you pay for renting
resources in the cloud, so performance really mattered. Also note that
users use whatever computing resources they have available to get their
job done, ideally at the lowest cost. Elegance of any OS architecture
is secondary, if that.