This KB article provide steps to clean up UBP data . The database has a large amount of outdated data (eg for users/devices) that no longer exist.
Symantec Risk Authentication 9.1.x
Below is the query to cleanup the UBP data for the users who are deleted from the system.
DELETE FROM XUBPDATA where (USERNAME,ORGNAME) IN (SELECT USERID,ORGNAME from ARUDSUSER_ARCHIVE);
The DBA should be involved if the ARUDSUSER_ARCHIVE table has large data (approximately 1M) to add the necessary indexes.
Customer with only a few records (approximately 1k or 2k) does not need an index.