Re: The fable of DEMETRIUS, CONSTRAINTICUS, and AUTOMATICUS
From: Kenneth Downs <firstinit.lastname_at_lastnameplusfam.net>
Date: Sat, 23 Oct 2004 21:12:36 -0400
Message-ID: <4ivelc.ivc.ln_at_mercury.downsfam.net>
>
> True, as far as it goes, but we can also consider code to be data, and
> data to be code. Any bytecode system is a formal mechanism for specifying
> code as data; the lambda calculus and Church numerals let us specify
> data as code.
>
> I think there's not much value to considering data to be code, but I
> do see value in viewing code as data, when appropriate.
>
> Why not? The where clause at least is perfectly consistent with
> querying the catalog. (I'm not sure I understand the FROM part.)
>
Date: Sat, 23 Oct 2004 21:12:36 -0400
Message-ID: <4ivelc.ivc.ln_at_mercury.downsfam.net>
Marshall Spight wrote:
> "Kenneth Downs" <firstinit.lastname_at_lastnameplusfam.net> wrote in message
> news:jma9lc.ner.ln_at_mercury.downsfam.net...
>> >> Code is recipes. They tell you what to do and you store them in a filing >> cabinet. Data is food, like flour and pies, you store them in the pantry >> and the refrigerator. When this distinction is not understood, you get >> paper in the fridge and flour in the filing cabinet.
>
> True, as far as it goes, but we can also consider code to be data, and
> data to be code. Any bytecode system is a formal mechanism for specifying
> code as data; the lambda calculus and Church numerals let us specify
> data as code.
>
> I think there's not much value to considering data to be code, but I
> do see value in viewing code as data, when appropriate.
I would contend that it is never appropriate to consider SQL code to be data, it simply is not.
>
>
>> Or another example. I can do this: >> >> CREATE VIEW new_columns AS >> SELECT column_id FROM dd_columns >> WHERE column_id_existing IS NULL >> >> but I cannot do this: >> >> SELECT features FROM file:///BigBunchOfDDL.SQL >> WHERE Columns ARE Numeric >> AND columns HAVE Constraints
>
> Why not? The where clause at least is perfectly consistent with
> querying the catalog. (I'm not sure I understand the FROM part.)
>
the FROM clause is a disk file full of SQL statements, or perhaps if you like Java or C#. You cannot query this information with SQL, because it is not in tables. Moreover, it is of a fundamentally different nature and does not even contain the same kind of information.
-- Kenneth Downs Use first initial plus last name at last name plus literal "fam.net" to email meReceived on Sun Oct 24 2004 - 03:12:36 CEST