Re: Designing database tables for performance?

From: Bob Badour <>
Date: Tue, 06 Mar 2007 19:43:32 GMT
Message-ID: <EvjHh.7139$>

Anne & Lynn Wheeler wrote:

> paul c <> writes:

>>I don't remember when I first heard or read the term "logical I/O".
>>It might have been the in the early 1970's when IBM's VSAM access
>>method first hit the streets.  I'm pretty sure it was current in some
>>circles then.  Codd had written his first papers then but practically
>>nobody in industry was even aware of them as IBM was pushing IMS and
>>Vandl hard and people who knew him then told me later that there were
>>big marketing forces at IBM that made working at the same company very
>>difficult for him both personally and professionally.  The term is a
>>very unfortunate one since I'm sure misleads many newcomers to IT.  As
>>we can see here, it misleads many others.
>>(Anybody who was programming then has an historical advantage over
>>younger people because it is so much easier to see what a revolution
>>Codd started.)

> original relational/sql implementation was system/r done all on
> vm370 ... misc. collected posts mentioning system/r activity:
> recent thread mentioning various things from system/r days:
> Jim Gray Is Missing
> Jim Gray Is Missing
> Jim Gray Is Missing
> Jim Gray Is Missing
> Jim Gray Is Missing
> vm370 was a follow-on to cp67 ... what had implemented both virtual
> memory and virtual machines in the mid-60s ... done at the cambridge
> science center. some of the people from CTSS had gone to the science
> center on the 4th flr of tech sq (worked on cp67, cms and other things)
> GML (precursor to sgml, html, xml, etc) was also invented at the
> science center in 1969.
> others from CTSS went to the 5th flr and worked on multics. the
> multics group managed to bring out the first commercial relational
> database product (MRDS):
> it was into the 80s before tech. transfer from SJR to Endicott
> succeded with SQL/DS product ... and even longer for tech. transfer of
> SQL/DS from Endicott back to STL for DB2.
> when virtual memory for 370 was announced, for whatever reason, they
> chose the term "virtual storage" (instead of virtual memory) ... from
> that comes dos/vs, vs1, vs2, svs, mvs, vsam, etc (all the "VSs")
> various past posts mentioning quote from the mid-60s about "A system
> of that period that had implemented virtual memory was the Ferranti
> Atlas computer, and that was known not to be working well"
> TSS ancient history, was X86 ultimate CISC? designs)

> VM: checking some myths.
> TECO Critique
> a.f.c history checkup... (was What specifications will the standard year 2001 PC have?)
> Disk drives as commodities. Was Re: Yamhill
> SR 15,15 was: IEFBR14 Problems
> Robert Creasy, RIP
> virtual memory
> lots of collected posts mentioning virtual memory, demand paging, and
> replacement algorithms (virtual memory and/or various kinds of "caches")

Hi Lynn,

The above post sat in my newsreader marked unread for quite a while to remind me I wanted to dig deeper when I was better rested. I did some spelunking through the links above and other links at

Some of the Boyd stuff is really interesting and thought-provoking.

Thank you! Received on Tue Mar 06 2007 - 20:43:32 CET

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