Re: 4 the Faq: Strengths and Weaknesses of Data Models
Date: Fri, 15 Oct 2004 08:06:35 -0400
Message-ID: <3Z6dnbE4VanFIPLcRVn-pw_at_comcast.com>
"Marshall Spight" <mspight_at_dnai.com> wrote in message
news:E4Hbd.260473$3l3.250666_at_attbi_s03...
> "Laconic2" <laconic2_at_comcast.net> wrote in message
news:AvCdnQKK88xZWfPcRVn-vw_at_comcast.com...
> >
> > Of course, DEC SW engineering interpreted "relational DBMS" in ways
that
> > some in this crowd dismiss as heretical or, even worse, commercial. Now
ask
> > me if I care.
>
> Tell, tell! *What* did they do to the RDM that was heretical and/or
> commerial? Was it good or bad?
They added support for SQL in version 3. I think they wanted to compete
with IBM. Just using SQL as an interface is enough to earn the wrath of the
relational bigots around here.
It was possible to define a "relation" that would violate 1NF.
They had a datatype called "DBKEY". This was really a pointer. This meant
that you could build your own network or hierarchical database underneath
the relational database if you wanted to. DBKEYs stored in records suffer
from all the problems with the graph data model that are outlined in the
Their DML was really not a PL. In order to do "real programming", you needed a "real programming language".
This is off the top of my head. I might think of more, later. Anyway, all the people in here who dismiss the commercial relational DBMS products of the early 1980s as "not relational" would have done the same think with Rdb, I imagine.
There are several things that I think, in retrospect, they could have done better. But there are an enormous number of things they got right, and that I just took for granted, because it was my first DBMS! Received on Fri Oct 15 2004 - 14:06:35 CEST