Re: Reminder, blatant ad
Date: Fri, 10 Feb 2006 21:50:43 GMT
Message-ID: <TU7Hf.248159$P64.7755830_at_phobos.telenet-ops.be>
dawn wrote:
>
> I'd like to better understand data independence in terms of
> functionality.
>
> Does it mean that if a new version of a DBMS tool takes the same
> logical specification it can lay the bytes down differently on the disk
> without application code changing?
No.
> Or does the decoupling of physical and logical mean that if I want to
> store attribute data physically "along with" a different entity (table)
> than where it is now (and rework the logical model), no application
> software needs to change?
No.
It means that you can make some changes in the physical model w/o having to change the logical model. Note that this is different from what you just said because you were talking about the logical model.
> I'm likely confused on this topic as I have not studied it in depth.
You probably should. It is the singlemost important notion for understanding what the relational model is about.
- Jan Hidders