Maybe I missed something, but why wouldn't an ID field work as the unique key ? :-)
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message: 5
date: Mon, 28 Jan 2013 17:58:48 +0000
from: "Stone, Joel" <Joel.Stone@xxxxxxxxxx>
subject: RE: Uniquely identifying a record in SQL without a unique
key?
RRN is probably not a good entity to use for database development. It is a crutch in the Iseries world that probably should not be used. It is probably as useful [to an iseries developer] as knowing the drive sector that a record currently resides on.
It fails as an identifier of a row, mainly because it is not immutable - ie it can and does change for a given row.
So ages ago high-quality database designers set up a simple immutable key structure with an auto-incrementing sequential immutable key. Unfortunately DDS has never provided this, so Iseries developers try to make up their own. Often they tie the sequential key to an item#, customer#, invoice#, etc.
That is when things start sliding downhill.
I think that all the better database engines out there today provide a simple mechanism to create an immutable auto-incrementing key for each record. Even the JDE type toolsets provide this.
Iseries only provides it when creating files with SQL, which is probably a small percentage of files in the iseries world.
So, on other platforms, RRN just gets people in trouble and database designers [outside the iseries world] most likely frown upon its use and try to hide it from developers.
My 2 cents anyways.
midrange.com
