johnnyb@eskimo.com (Jonathan Bartlett) writes:
> However, the reason the industry switched to relational databases
> was that they cared more that they had consistent data that worked
> with multiple applications that was able to guarantee data integrity
> (i.e. - support for views, constraints, and triggers) than they were
> about speed. In fact, the first relational databases were 50x
> slower that their hierarchical and network counterparts. However,
> the industry still switched because data integrity and data
> independence is worth that much.
If I understand the history of things correctly, a big part of the
reason why the industry switched from IMS to DB/2 and Oracle was that
they could live with the manyfold diminishment of performance, but
desperately needed to have the flexibility that RDBMSes bought them.
The IMS applications, where navigation and validation logic had to be
hard-coded into the applications, were getting to be too much to cope
with.
I suspect that the Telco folks are still fighting with this to some
degree even to this day; everyone I have known that has been involved
with telco billing applications have found them to be an absolute
horror. A few years ago, I observed cases of them being unable to
offer the new products that Sales were selling because they couldn't
integrate in the code to support BILLING for the new services...
There was a coworker at SHL Systemhouse that kept getting stuck back
on an infamous such project after regular promises that "this will be
the VERY LAST TIME." After 3 "last times," he quit and moved to New
Zealand so they couldn't call him again. :-)
It seems to me that what we are observing here is that "youngsters"
with neither an interest in history nor the maturity of having
experienced some "IT war wounds" are heading in the very same
directions as the IMS people of the '60s.
There are big enough challenges when we use every bit of integrity
checking that we can get our hands on; when no attempt is made to do
it, that's just disaster.
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Christopher Browne
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