[Info-vax] OpenVMS async I/O, fast vs. slow

[Arne Vajhøj]

On 11/5/2023 6:14 PM, bill wrote:
> On 11/5/2023 4:50 PM, John Dallman wrote:
>> Incidentally, the situation for Fortran is rather different from COBOL
>> and PL/I. Academic computer scientists don't usually touch it, but
>> physicists, computational chemists and the like still use it heavily. So
>> there are still people coming onto the job market who know it.
> 
> Yes, but how well (and I don't mean syntax)?  Who is teaching them?
> If they are not getting this training from CS Departments are they
> getting any of the fundamentals or just syntax?

Scientific computing is pretty different from business applications.

I don't think trying to apply best practices for business applications
to scientific computing makes sense.

The business application will need to be maintained 10-20-30-40-50
years with constantly changes.

Many scientific applications (not scientific libraries those are
different and more like business applications) only need one
successful run and then the code goes on the shelf for future
copy paste.

Very different contexts.

Fortran was very widely used back in the days in physics, astronomy,
chemistry, biology, medicine, economics etc..

Some probably still use Fortran.

But a lot of that stuff are done in Python today. Today
Python is the language for scientific computing.

Note that the interpreted Python is of course only
"orchestrating" the number crunching - the number crunching
itself are done in native code - Fortran, Fortran converted to C
(yes!) or C.

So the Fortran code still exist, but the scientists don't use
it and don't even see it.

> Some of the worst business programs I ever had to work with were in
> Fortran and written by engineering faculty who needed something to do
> during the summer.

Writing a business application in a language designed for
scientific computing by people with mostly scientific
computing experience has a very low chance of success.

Writing a nuclear explosion simulation in Cobol by
people with expertise in ISAM files and BCD would probably not
go well either.

Arne