Meaningful surrogate primary keys

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. Received on Thu Mar 20 2003 - 17:46:56 CST