Re: Foreign key in Oracle Sql

DA Morgan wrote:

> ... How could a table, in
> advance, know the cardinality of the data that will be loaded into it?

that's not the question, rather it is why shouldn't the dbms always (don't worry about knowing 'in advance') know the cardinality and then choose what to do about it!

> Perhaps a crystal ball? Or how about data skew? A built in Ouija board
> function? ... Taro cards?

these don't sound like computer techniques to me.

> Some day you'll get exactly what you want. No doubt Microsoft will sell
> it to the same people that currently think MS Access is a database.

apologies, i thought you had been touting Oracle.

> And
> it will perform as abysmally as all similar products do and be relegated
> to being the butt of jokes.

agree, they're all abysmal if one believes missed function is as much poor performance as silly function done well.

eg. right now, the industry is spending a lot of effort and otherwise to try to model unknown knowledge, some with Nulls and some with Objects. i hardly think we are ready for pedantry when the state of the art is so immature (ie. when even the basic questions haven't been posed coherently).

p Received on Fri Jan 21 2005 - 21:25:17 CST