Re: Surrogate numeric keys versus natural character keys.

Hiya Connor,
thanks for the reply. I still have a couple of questions though! :)

Connor McDonald wrote:  

> Bad things with synthetic keys
> - you typically need to index the 'real' key anyway so updates are
> slower.
> - the 'real' will not be contained in subordinate tables

I can live with both of these side-effects if there is a significant performance benefit when performing complex selects from multiple tables which join to the customer table. Where can I web page which discusses these kinds of performance issues?

> Good things with synthetic keys
> - you can use reverse indexes

What is a reverse index? (You'd never guess I wasn't a DBA would you? :))  

> - as levels of subordinates grow, the primary key indexes will be
> smaller on the subordinates

This is assuming you use a surrogate/synthetic key at each level of subordination, right?

> - you can update the 'real' key

I guess it's really just the performance end of things that I am interested in, I was pretty much aware of most other benefits (though I'd never heard of a reverse index).

Thanks for the help,
Alan. Received on Thu Aug 10 2000 - 00:00:00 CDT