I would modify the row level restrictions assigned to a Role using the following VQL command,
* First, revoke the existing privilege,
`ALTER ROLE <role_name> REVOKE EXECUTE when() then 'column_name = search_value OR column_name = search_value’ on <db>.<view_name>;`
* Then, alter the role with the new set of row level restrictions using the below command,
`ALTER ROLE <role_name> GRANT EXECUTE on <db>.<view_name> GRANT EXECUTE when() then 'column_name = search_value’ on <db>.<view_name>;`
Modifying the role privileges this way would remove the existing row level restriction and add the newly created restriction.
For more information, take a look at the [Granting Privileges to a User/Role](https://community.denodo.com/docs/html/browse/8.0/en/vdp/vql/creating_databases_users_roles_and_access_privileges/managing_users/modifying_the_privileges_of_a_user#granting-privileges-to-a-user-role) section of Virtual DataPort VQL Guide.
Hope this helps!