Refrshing a materialized view in oracle

The DBMS_SNAPSHOT package is providing us a procedure to refresh the materialized view in oracle.

BEGIN
DBMS_SNAPSHOT.REFRESH('VIEW_NAME','c');
END;

The first parameter is the view's name and the second parameter is the refresh option.
c - complete refresh
f - fast refresh

If you exexcute the above block the view will be refreshed.