READ Locks and Cancelled Rollback Operations
When you use the RcvManager utility to cancel a transaction rollback, the system marks the base table on which the rollback was cancelled as nonvalid. As a result, the table cannot be updated. With some restrictions, you can inspect the rows of the non‑valid base table if you specify a LOCKING FOR READ OVERRIDE modifier.
The following rules document the restrictions on the use of a LOCKING FOR READ OVERRIDE modifier: