Re: Meaningful surrogate primary keys

MnM wrote:

> I've a hierarchy (dept of more than 4-6 tables) of tables with
> parent-child relationship. In OO terms, you can think of it as
> ‘composite' relationship. I'm using meaningful surrogate PK for each
> table, such that PK of table A will be a FK in table B and will be a
> part of B's PK and same with table C i.e. B's PK is C's FK and also
> part of C's PK. Here is an example:
>
> Tables (in parent-child sequence): A, B, C
>
> Table A: PK = aa
> Table B: PK = aabb FK = aa
> Table C: PK = aabbcc FK = aabb
>
> Now, I want to know, does it effects performance in Oracle when
> surrogate keys are lengthy e.g. 20+ chars? If it does, please suggest
> a good solution.
>
> Thanks.

Almost by definition it must. But the question is really one of significance. Something that can only be known by looking at specific usage, transaction volume, etc.

Daniel Morgan Received on Thu Mar 20 2003 - 19:19:33 CST