InterSystems FAQ rubric
There is data, such as execution log data, that you do not want to return to its previous state even if a rollback occurs during a transaction. The above requirement can be met by placing that data in the IRISTEMP database, which will not be rolled back.
Temporary Globals and the IRISTEMP Database
By mapping the table entities you do not want to roll back to this database, you can retain the information after the rollback.