RE: Indexed PF vs. LF performance

Isn't RRN a valid identity key in the instance of logging files? Yes, a REORG can change the RRN but there is a way to uniquely identify a record

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Joe Pluta
Sent: Tuesday, July 31, 2012 1:02 PM
To: Midrange Systems Technical Discussion
Subject: Re: Indexed PF vs. LF performance

In my case, I would make that architecture decision based on requirements. Consistency is a consideration but not an overriding one. Like anything else, identity keys should be used where appropriate. The trick is deciding when they are appropriate, and that can be different for different circumstances.

Joe

Why wouldn't it? If all your other tables have identity keys, why
would you leave one table without identity keys?

On Tue, Jul 31, 2012 at 10:24 AM,<rob@xxxxxxxxx> wrote:

Define "need".
It's not required in the CREATE TABLE.

But I agree that almost all tables should have a "primary key" constraint.
Why would one need one on a transaction history file though?
I agree that, in general, an identity column works well for a primary key.
I can bend on that. For example a table of states. Why should IN,
Indiana have an identity column as it's primary key?