Re: E pluribus unum, was: identity columns

In about 1980, I began working in a language called "Datatrieve". This ran on DEC PDP-11 computers,
and on VAX/VMS. Datatrieve operated on data stored in indexed files, but it did have a primitive operator called "cross" that implemented the relational join. It also had a "with" clause that used a predicate to select sets of records, like the "where" clause of SQL.

Datatrieve marked my transition from traditional programming to relational databases.

A few years later, DEC made its entry into the relational database arena with a product called "Rdb". Rdb was (and still is) a relational database. Its interface language was called "RDO". RDO's data manipulation statements were heavily influenced by Datatrieve.

In about 1986, a version of Rdb was released with support for SQL as well as RDO. Eventually, SQL became the primary interface, and RDO was kept around only for the sake of old applications. Rdb became known as "Rdb/VMS", and eventually a version was produced to run under DEC Unix.

DEC's Rdb product was sold to Oracle in 1994. Oracle renamed it "Oracle Rdb". Last time I checked, Oracle Rdb STILL had support for RDO as an alternate interface to SQL.

I hope this helps place RDO in context.

Regards,

    David Cressey
    www.dcressey.com
"--CELKO--" <71062.1056_at_compuserve.com> wrote in message news:c0d87ec0.0202041621.34700b82_at_posting.google.com...
> >> My first relational interface was a language called "RDO" ... <<
>
> That is one I do no remember at all! I think I have a QUEL manual in
> the garage, but I would really have to dig for it.
Received on Tue Feb 05 2002 - 04:56:20 CET