Re: Natural keys vs Aritficial Keys

toby <toby_at_telegraphics.com.au> writes:
> If expressing exact rationals is what you want, then that is trivially
> done using integer arithmetic - as is fixed point decimal. Hardware
> decimals, which essentially died with the VAX, don't help you express
> rationals.

decimal hardware as one of the things that differentiated commercial & scientific/defense machines back in the 50s

recent thread in a.f.c. discussing 650 (commerical, announced 1953) and 701 (defense calculator announced 1952)
http://www.garlic.com/~lynn/2009h.html#12 IBM Mainframe: 50 Years of Big Iron Innovation

360s bascially converged the scientific and commercial lines ... providing hardware support for decimal operations ... in addtional to binary and floating point.

the person responsible for rexx language ... did a lot of the work on decimal floating point standard ... recent reference (in comp.arch) http://www.garlic.com/~lynn/2009e.html#84 Decimal roolz, was Architectural Diversity

references IEEE decimal floating-point specification http://www2.computer.org/portal/web/csdl/doi/10.1109/ARITH.2001.930114

and some number of decimal floating-point articles from wiki page
http://en.wikipedia.org/wiki/Mike_Cowlishaw

when Jim left for tandem ... he tried to hand off consulting with IMS on me ... old email reference:
http://www.garlic.com/~lynn/2007.html#email801016

recent reference
http://www.garlic.com/~lynn/2009g.html#15 Confessions of a Cobol programmer

there is still quite a bit of Cobol use ... recent thread which will make heavy use of hardware decimal support (if available):
http://www.garlic.com/~lynn/2009g.html#12 Cobol hits 50 and keeps counting

quote from referenced article

Some 75% of the world's businesses data is still processed in Cobol, and about 90% of all financial transactions are in Cobol, according to Arunn Ramadoss, head of the academic connections program at Micro Focus International PLC, which provides software to help modernize Cobol applications.

... snip ...

decimal instructions (dating back to 360s) section in recent mainframe principles of operation
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9ZR003/8.0?SHELF=DZ9ZBK03&DT=20040504121320

-- 
40+yrs virtualization experience (since Jan68), online at home since Mar1970