Re: Reusing Deleted Records in a File (REUSEDLT)

rob@xxxxxxxxx wrote:

Does anyone process by RRN anymore? I remember Mapics on a S/34
used to use "chain chase" sequence on their bill of materials and
use RRN but I'd like to hope they don't anymore.

Often such implementations differ little from having an /identity/ column [SQL] used as a key. The same potential for problems exist both referentially to data within the database and when the data is used outside of the database; e.g. the key value is used as a label to identify a physical item outside the database.

So if an application uses the internal key maintained by the database as RRN, there is nothing inherently wrong with that application. The application /can/ make it work. What is really /wrong with/ such implementations, is its _assumption_ that no changes to its data would be implemented _outside the application_ which might /break/ the application. The RRN is worse, for its inability to be used in maintaining referential integrity by that internal key. The only fatal flaw I can figure with RRN is if the physical row is responsible for /damage/ [partial damage] to the file, such that a row is not accessible; i.e. it would not be possible to simply add a new row as replacement, pending its recovery by delete, restore, & apply journaled changes.

Regards, Chuck