Re: Conceptual, Logical, and Physical views of data

From: Marshall Spight <>
Date: 11 Sep 2005 07:51:02 -0700
Message-ID: <>

David Cressey wrote:
> I agree that Marshall is doing fine.

<blush> Thanks guys!

> First, I don't scorn SQL the way true relational bigots do.

I feel similarly. I really like SQL; the ability to joins, for example, is an awesome power. I kind of feel about SQL the way I feel about Java: sure it could be better, but there are a lot of *worse* things out there, so I'm glad of what I've got.

> Second, I don't think that all programming should be done in a database
> language like SQL, or that all programs should be under the aegis of a DBMS,
> like stored procedures in an Oracle database.
> [...]
> SQL is simply not general enough to
> replace all general purpose programming languages. And attempts to make it
> that general simply interfere with its primary mission, which is to serve as
> an interface language for data exchange.

While I agree that that's the right choice in today's environments, I firmly believe that it is *possible* to design a language for which that would not be true.

Today, one has many useful abilities one can do with SQL: joins, content-based addressing, declarative integrity constraints. In Java (for example) one has a completely different bag of tricks: polymorphism, inheritance, modularity, etc. Why must the two sets of techniques be completely distinct? Why can't I have a language that is simple yet powerful, and gives me the union of these capabilities?

> Third, I don't elevate the logical model to the level of idolatry
> that some relational bigots do.

> Fourth, I don't believe that relational database theory is
> the end point of all history, as far as advancements in
> the fundamental state of the art.

To me, set theory is the "beginning point" of all (math/CS) history. Relational theory builds from that. Mikito recently commented about just how undeveloped relational algebra is; I agree. I think one thing that's going to happen is that it will get more developed.

> In particular, I expect "computer database theory" to eventually
> come up with something that relegates the relational model to history.

Given how foundational set theory is, I'm not sure I agree. I am sceptical that we'll ever stop using, say, boolean algebra. Likewise I expect that the programming languages of the future will have something like join in them.

Marshall Received on Sun Sep 11 2005 - 16:51:02 CEST

Original text of this message