On 2013-08-30 16:04, zMan wrote:
If you need one, there's always
http://www.ebay.com/itm/IBM-Model-83-Punch-Card-Sorter-/300954726197?pt=US_Vintage_Computers_Mainframes&hash=item46124caf35
At 16:28 -0600 on 08/30/2013, Paul Gilmartin wrote about Re:
Sortlessness?:
And it operates in time linear with respect to the size of
the input data set, implying that for a sufficiently large
input data set it will outperform most competing technologies.
-- gil
Robert A. Rosenberg addded:
I think that should be "it operates in time linear with respect to the
size of the input data set TIMES THE LENGTH OF THE SORT
FIELD". IOW:
The actual time (ignoring the time it takes to collect the 12 stacks of
cards and putting them back into the feed tray for sorting on the
next column) is the same as a single column/pass sort of a deck whose
size is X times as large (where X is the number of columns you are
sorting on).
FWIW...alpha-numeric columns need 2 passses through the sorter !!
I think it shold be "it operates in time linear with respect to the
NUMBER OF CARDS TIMES the SUM of the sort field columns
PLUS the number of alpha-numeric columns in the sort field. The
latter includes the number of numeric field columns with +/- sign."
e.g. request for some report sorted on:
cc.71-72 Prov/State and cc.11-16 Date MMDDYY
requires *10* passes through the sorter in this order:
sort N on cc. 14, 13, 12, 11, 16, 15, 72
sort Z on cc. 72
sort N on cc. 71
sort Z on cc. 71
Say 20'000 cards / 1000 cpm = 20 min / pass, 3:20 hrs total
excluding card jams, human errors, ...
Andreas Geissbuehler
