Re: WWW/Internet 2009: 2nd CFP until 21 September
Date: Mon, 10 Aug 2009 18:10:28 GMT
Walter Mitty wrote:
> "paul c" <toledobythesea_at_oohay.ac> wrote in message
>> Walter Mitty wrote: >>> ... >>> The relational view of data as regards data in transit over a network >>> extends the scope of discussion of the relational model beyond the scope >>> contemplated in 1970. The discussion in 1970 and for many years >>> afterwards focussed on the application of the relational model to the >>> organization of data banks for large scale sharing of data. Large scale >>> sharing of data is increasingly being carried out by shipping data over >>> the network from one system to another. Any databases involved are in >>> the background. >>> ... >> In the 1960's, let alone the 1970's, "large scale sharing of data" by >> people was already a given requirement, no matter whether the vehicle was >> hierarchies or graph designs. The more urgent problem, recognized even by >> the Codasyl people, was sharing of data by applications..
> First, I've always taken the word "user" in the 1970 paper to apply to an
> application program, or to a fairly transparent command and print utility,
> or to a human using the database as mediated by either an application of a
> utility program. My reading might not have been careful enough.
> Second, as to whether sharing was a given requirement or not, I'd have to
> say that it depended on who you talked to. A large part of my career from
> 1985 through 1999 consisted not only in enabling people to share data, but
> in convincing people of the merits of doing so. In almost every client
> company there was a large faction that stood to lose, or thought so, if data
> sharing prevailed. Even today, I'd say that over half of the databases
> being built in SQL server are planned for use only by a single application
> inside which the database is to be embedded. ...
No doubt, but I think Codd was emphasizing that even an individual application becomes more clear to the user, or observer if you prefer, if it uses his few simple universal manipulators.
I think he would have said that political territory and not-invented-here attiitudes don't change that advantage.
Any use of the data by other
> applications, or even by general purpose report generators or OLAP
> environments is to be done through the app's API.
> The fact that such a view is monstrously naive doesn't prevent it from being
> the majority view. Add to that the marketing plan that says that the client
> has no choice but to return to us for access to their own data, and you
> have the road to hell, well paved.
Speaking of apps being 'users', I remember an airline that invented an api with fourteen verbs so that the flight control system could notify cargo process control at various destinations. Nobody thought to include a verb that would handle the re-routing of a plane after it had taken off, eg., because of bad weather at the destination. The funny thing was that only four smallish tables were involved and they were more or less duplicated at each end of a flight. It would have been simpler to send every insert, delete or update of those tables to the destination computers, echo the tables at both ends and let each applicatiion decide whether it should ignore or reflect the message, eg., four tables and three message types. Supplier said that couldn't be done! Received on Mon Aug 10 2009 - 20:10:28 CEST