Re: object algebra
Date: Wed, 25 Feb 2004 08:22:37 GMT
Message-ID: <hXY_b.56566$4o.75850_at_attbi_s52>
"Neo" <neo55592_at_hotmail.com> wrote in message news:4b45d3ad.0402242223.6e84d475_at_posting.google.com...
> > > It is not that you cant represent 4-th dimensional, trees and complex
> > > data structures using the "rectangularish" building block provided by
> > > RDM, it's just more difficult and sometimes impractical.
> >
> > I disagree that it's more difficult. Trees are easy.
>
> Will you implement an equivalent NULL-less solution to the example
> posted at www.xdb1.com/Example/Ex076.asp so that we can establish
> this?
Here's my first cut. I reserve the right to change my design later. No nulls were used. I have to admit your test data made me feel a bit silly.
create table EX76 (subject varchar(80), relator varchar(80), object varchar(80));
insert into EX76 values ('obeys', 'isa', 'relator'); insert into EX76 values ('god', 'isa', 'thing'); insert into EX76 values ('god', 'equals', 'god'); insert into EX76 values ('it', 'is', 'obeys'); insert into EX76 values ('force', 'isa', 'thing'); insert into EX76 values ('army', 'isa', 'force'); insert into EX76 values ('church', 'isa', 'thing'); insert into EX76 values ('trinity', 'isa', 'church'); insert into EX76 values ('person', 'isa', 'thing'); insert into EX76 values ('john', 'isa', 'person'); insert into EX76 values ('mary', 'isa', 'person'); insert into EX76 values ('luke', 'isa', 'person'); insert into EX76 values ('age', 'isa', 'thing'); insert into EX76 values ('35', 'isa', 'age'); insert into EX76 values ('john', 'is', '35'); insert into EX76 values ('weight', 'isa', 'thing'); insert into EX76 values ('130', 'isa', 'weight'); insert into EX76 values ('mary', 'is', '130'); insert into EX76 values ('color', 'isa', 'thing'); insert into EX76 values ('red', 'isa', 'color'); insert into EX76 values ('luke', 'is', 'red'); insert into EX76 values ('dog', 'isa', 'thing'); insert into EX76 values ('fido', 'isa', 'dog'); insert into EX76 values ('computer', 'isa', 'thing'); insert into EX76 values ('laptop1', 'isa', 'computer'); insert into EX76 values ('army', 'obeys', 'god'); insert into EX76 values ('trinity', 'obeys', 'god'); insert into EX76 values ('john', 'obeys', 'army'); insert into EX76 values ('mary', 'obeys', 'army'); insert into EX76 values ('mary', 'obeys', 'trinity'); insert into EX76 values ('luke', 'obeys', 'trinity'); insert into EX76 values ('laptop1', 'obeys', 'john'); insert into EX76 values ('laptop1', 'obeys', 'mary'); insert into EX76 values ('fido', 'obeys', 'john'); insert into EX76 values ('fido', 'obeys', 'mary'); insert into EX76 values ('fido', 'obeys', 'luke');
Marshall Received on Wed Feb 25 2004 - 09:22:37 CET