http://www.nou.edu.ng/noun/NOUN_OCL/...t%20System.pdf

"IBM started working on a prototype system loosely based on Codd's
concepts as System R in the early 1970s — unfortunately, System R
was conceived as a way of proving Codd's ideas unimplementable, and
thus the project was delivered to a group of programmers who were not
under Codd's supervision, never understood his ideas fully and ended up
violating several fundamentals of the relational model."

People who knew him have told me stories about how various non-technical
IBMers tried to obstruct or even sabotage Codd, not just attacking his
ideas but him personally. This is the first I've seen in print that the
official proof of concept was deliberately set up to fail. No idea
whether it's true, didn't see any backup for one or two other claims
either. I suppose it's patently true that this particular team couldn't
implement his fundamental ideas. Maybe this was partly because he did
leave certain doors open, mentioning 'further research needed' or
suchlike here and there. But I've always had the impression that the
System R people just didn't recognize which doors were open and which
were closed.

On 22 nov, 02:47, paul c <toledobythe... (AT) oohay (DOT) ac> wrote:
exemplifies the universal nature of Codd's work...Tha sabotage part is
no surprise and should be part of science history. The honesty of
Codd's to clearly state the limits of his discovery was the behavior
of a scientist obsessed with truth rather than context.

The text in question (the whole document, I expect)
is copied without credit from the wikipedia.
The text starting "— unfortunately, System R
was conceived as a way of proving Codd's ideas unimplementable"
was removed 3 February 2009.
Perhaps someone more wiki-savvy than I
could find out more about its insertion and deletion
(and inserters and deleters).

philip