Re: Hashing for DISTINCT or GROUP BY in SQL

From: paul c <anonymous_at_not-for-mail.invalid>
Date: Mon, 18 Oct 2010 14:33:47 +0000 (UTC)
Message-ID: <i9hlsa$o2n$>

On 18/10/2010 2:31 AM, Cimode wrote:
> As years pass by and database science goes further and further into
> collective IT industry amnesia, I somehow believe*old timers* (note
> that I do consider myself an old timer) have simply failed to explore
> the opportunities openned by Codd, and remained, implementation wise,
> too bound to the IBM historical context of how relational
> implementation is to be conceived. Such lack of perpective limited RM
> expressive power and constrained it(unhappy pun!) to empirism rather
> than applying it to how we conceive information encoding as a whole.

I remember a lot of amnesia! I posed a question I was curious about even though it is probably pointless today, to the folklore usenet group, about the origin of the term 'field' as applied to file systems.   It might have been an unfair question since that group is mostly interested in the cultural history of hardware and operating systems as opposed to all software, but I thought it was more apt for that group than this one. There are several mathematical definitions for the term 'field' but the term also dates back to the 1940's use of Hollerith punch cards and possibly much earlier for all I know (I remember seeing punched cards that had pre-printed 'nested fields', eg., telephone number might have sub-fields of area code and number.

Anyway, it may be because I wrote the question badly, but so the reaction of that group seems to be that there was no mathematical inspiration behind the term. I had guessed that possibly the originators of Fortran might have thought it had special meaning being that the early Fortran files often consisted solely of numbers of different kinds and there is a definition of a 'closed field' of numbers that some mathematicians use. But logicians at one time also used the term to describe the union of what they called 'converse domains'. Maybe neither influenced the computer use of the term but so far nobody seems certain of that. Received on Mon Oct 18 2010 - 16:33:47 CEST

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