How the parameter atomic_refresh in dbms_mview.refresh will make the refresh faster?
a. when atomic_refresh is set to FALSE, the materialized view is deleted with DROP command.
b. when atomic_refresh is set to TRUE, the materialized view is deleted with DELETE command.
c. When atomic_refresh is set to FALSE, the materialized view is deleted with TRUNCATE command.
d. When atomic_refresh is set to TRUE, the materialized view is deleted with TRUNCATE command.
