Re: The C in ACID

paul c wrote:

> I don't see a conflict. Perhaps you see a subtlety I don't. I consider
> the facts in a db correct if they are consistent with whatever
> constraints I've specified. If a user enters an untruth, there's nothing
> the dbms can do about it, unless it has been told, eg., with
> constraints, how to recognize certain lies.

I was under the impression the terms Correct and Consistent had precise, well-defined and even generally agreed upon definitions with respect to the relational model. For example, in CJ Date's 8th edition:

"Correct implies consistent (but not the other way around) and inconsistent implies incorrect (but not the other way around) where by correct we mean the database is correct if and only if it fully reflects the true state of affairs in the real world"

Obviously my impression was wrong.

It does seem a little strange that Lomet and Barga would have the C in ACID mean correctness, (even if they call it consistency), and then say that the DBMS can't enforce it. Why bother having C in the acronym if it can't be enforced? Received on Mon Aug 21 2006 - 19:48:22 CEST