Re: A searchable datastructure for represeting attributes?

"Ilya Zvyagin 2147483647" <ziv_at_fct.ru> wrote in message news:1014979926.653000_at_gatekeeper.fct.ru...
> Hello, Nuno!
> You wrote on Fri, 01 Mar 2002 10:12:45 GMT:
>
> NS> What makes them more efficient by moving them away from the data
> NS> they are supposed to keep the integrity of?
>
> Let's think of a situation when we need to add a new
> domain to our relational DB with some very odd rules
> for its possible values.
>
> F.e. ISO container numbers (what is familiar to me)
> should have a verifying digit at the end.
>
> And please don't say anything about triggers.

Why not? seems to me that a trigger encoding the validation logic is *exactly* what you would want here.

The other logical place for this sort of validation might be in the presentation layer of the application, though I think it is not unreasonable to suggest in this distributed world, and also to cope with people inserting data other than through the app, that you'd want validation code to reside both at the data entry layer (to remind the users) *and* at the data layer to ensure data integrity.

--
Niall Litchfield
Oracle DBA
Audit Commission UK
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