Re: Requirements for update languages?
Date: Fri, 8 Nov 2002 20:09:54 -0000
Message-ID: <aqh5o4$ukg$1_at_sp15at20.hursley.ibm.com>
"Jens Lechtenbörger" <lechtej_at_uni-muenster.de> wrote in message
news:m2k7jo87eh.fsf_at_pcwi1068.uni-muenster.de...
> Dear reader,
>
> while there are some criteria to assess relational query languages
> (adequate, relationally complete, optimizable) I wonder what makes a
> good update language for a data model.
>
> In particular, I wonder about the following points in SQL.
>
> 1. I believe that SQL data manipulations are not adequate for bags,
> as they lack the ability to manipulate duplicates. (E.g., you
> can neither delete 3 out of 5 duplicates nor insert 3 duplicates
> at once.)
> 2. As a db user, I expect that I can undo (inadvertent) data
> manipulations, e.g., undo an insertion via a deletion or vice
> versa.
> Does anybody else believe that this is a reasonable requirement?
No, I believe that is highly unreasonable. I you buy 5,000,000 shares you cannot just say, opps, didn't mean to do that - backout, you must sell them and hope you don't loose money.
> 3. As a db admin, I expect that users know what they are doing when
> they manipulate data.
> Does anybody else believe that this is a reasonable requirement?
No, I believe that is highly unreasonable. If all my database users had to pass am exam before using the db and had to sign a legally enforceable grantee that they know what they are doing, then I would not have very many db users. ;-)
> Basically, the anonymous referees did not buy (2) and (3).
Regards
Paul Vernon
Business Intelligence, IBM Global Services
Received on Fri Nov 08 2002 - 21:09:54 CET