The FLUSH QUERY LOGGING statement provides some advantages over BEGIN QUERY LOGGING and END QUERY LOGGING statements. The FLUSH QUERY LOGGING statement enables you to flush the various DBQL and TDWM caches at any time. You can submit a FLUSH QUERY LOGGING statement and specify whichever options you choose, and the result is a synchronous flushing of the specified caches.
FLUSH QUERY LOGGING also provides the advantage of flushing selected caches, which you cannot do by specifying periodic BEGIN QUERY LOGGING and END QUERY LOGGING requests. FLUSH QUERY LOGGING also enables you to flush TDWM caches, which can otherwise only be flushed by the database when its timer tells it to do so.