Re: integer id columns for all tables

garhone schrieb:
> Hi,
>
> Someone with greater expertise than I recently told me that it is best
> to have an integer primary-key for all tables in a database, even if
> the table already has some non-integer primary key, or some sort of
> composite primary key. If there is already a non-integer key, then
> create a new sequence column and set that as the primary key.
>
> Does anyone have an opinion on this and why?

Such an approach is very good for many applications and it does make sense to use it. Its main advantage is that it more or less successfully separates identification means (primary key in RM) from what is going to be identified.

For complex models it is frequently more convenient to have adequate more complex (non-primitive) identification means. Unfortunately, in most cases using such complex identifiers has more harm than benefits. And, again, the main reason for that is almost complete absence of means for separating two concerns:

• object semantic characterisation (entity modeling) and
• object identification means (identity modeling).

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