Re: Surrogate keys (Was: enums)

[Michael Glaesemann <grzm(at)myrealbox(dot)com>]

On Jan 13, 2006, at 21:42 , Leandro Guimarães Faria Corcete DUTRA wrote:

> If you still declare the natural key(s) as UNIQUEs, you have just made
> performance worse.  Now there are two keys to be checked on UPDATEs  
> and
> INSERTs, two indexes to be updated, and probably a SEQUENCE too.

For UPDATEs and INSERTs, the "proper" primary key also needs to be  
checked, but keys are used for more than just checking uniqueness:  
they're also often used in JOINs. Joining against a single integer  
I'd think it quite a different proposition (I'd think faster in terms  
of performance) than joining against, say, a text column or a  
composite key.

Michael Glaesemann
grzm myrealbox com