Magnetic tape filesystem

Fred Cisin cisin at
Mon Feb 9 15:52:58 CST 2015

On Mon, 9 Feb 2015, Peter Corlett wrote:
> JOOI, why was there such a need to sort large datasets back in the mainframe
> era?

Consider, for example, a national telephone directory.

But, what constitutes "large" has changed over the years.  At one time,
mainframes did not have much memory.

I tried to teach some of the basic concepts in a Data Structures And
Algorithms class.  Several students (from UC Berkeley) insisted that
the ONLY appropriate way to sort a dataset that was larger than RAM
was to increase the RAM of the computer.
'course there were also people who thought that the only appropriate
way to insert an additional record into a large file was to append it,
and then sort the file.  And then got upset when I explained that if they
were going to do that particular sort, then a properly designed bubble
sort would be superior to Shell/Metzner.

Grumpy Ol' Fred     		cisin at

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