Marsh Ray wrote:
> Lauri Pietarinen wrote:
>
>> The theory, indeed, does not say anything about buffer pools, but by
>> decoupling logic
>> from implementation we leave the implementor (DBMS) to do as it feels
>> fit to do.
>> As DBMS technology advances, we get faster systems without having to
>> change our
>> programs.
>
>
> I think you've identified why relational systems have been the
> overwhelming winner in the business environment. They allow vendors to
> provide an optimized but fairly general solution to the interesting
> problem of efficiently accessing and storing data on rotating magnetic
> storage, while at the same time presenting a programming model that's
> at just the right level for the business applications programmer.
>
> Relational theory or no, linked tables are typically conceptualized as
> a slight formalization of the spreadsheet, or (in earlier times)
> stacks of punched cards. As business computers evolved from more
> specific machines that could perform some relational operations on
> punched cards (sort, select, etc.), I think it's still sort of stuck
> in the collective unconscious of business to want to model their data
> this way.
I agree with you on that one. The punch cards history is well visible
in the fact that in IBM-mainframes, many files have
a width of 80 chars, which just happens to be the amount of characters
you could save on a punch card. And, yes,
tables are often thought of as a deck of index cards, something you
might have had in the past.
>
> I think relational theory is useful primarily to database
> implementers, students, and those few application developers who are
> after a deeply theoretical understanding of their tools. They're
> probably the ones reading this list.
>
> I suppose MV and other non-SQL data stores have their place in a
> certain niches (embedded systems, etc.), but the business world has
> already voted with it's feet.
What I sense is a longing for a unified environment, something that SQL
+ [your app programming environment] does not provide.at the moment.
Hence the affection to Pick and other niche environments?
Lauri