Hi,

> From: "hvlad"<hvlad@...>
>>> One of my data models use natural keys that can change overtime. How are
> foreign keys and cascades implemented in the latest version of Firebird? Is it
> like in a REAL rdbms where the foreign key is actually a internal pointer to the
> referenced table and cascades are "instant" no matter how big the database
>>
>> Could you point us to the documentation to the such "REAL rdbms"
>> where your statement is confirmed ?
>>
>> Regards,
>> Vlad
> ------- End of Original Message -------
>
> Here you go:
>
> http://en.wikipedia.org/wiki/Codd's_12_rules
>
> Oh, but wait. Rules 1, 2, and 8 imply relational databases must use values, not
> pointers? Oops!

Do they really?

Rule 1: The information rule:
All information in the database is to be REPRESENTED ...

IMO, represented here means "show to user" or smth. Not "physically stored".


Rule 2: The guaranteed access rule:
... individual scalar value in the database must be LOGICALLY
ADDRESSABLE ...

IMO here "logically" means "you get value this way", not "value is
stored this way".

Rule 8: Physical data independence:

Clearly states, that APPLICATION should not depend on the way the data
is physically stored. Whether it's values or pointers, application
doesn't care, right?


BTW, I support values, not pointers.

--
Aurimas