Using the following query to confirm that the datafile number mentioned in the error is for NH_INDEX.
select file#, name from v$datafile;
The ORA-01578 error message will not persist, because the block will not be accessed again after a brief period. If there is a concern that this needs to be fixed immediately (for example, if error being seen repeatedly due to some job run ad hoc just after the load), then the following command can be run to resolve the issue:
This command can take a long time to run, so it is generally not advised to run it.