expand topfilter filter

topfilter creates files for every count statements for every session_id

"The session ID is added to the filename for each file written."

This can cause many files,
which flooded the disk and difficult to analyzed.

So
single_file = ON (default off)

Stores all in a single file (append) instead files for every session.

timeframe = seconds

If set, all queries will be saved for all sessions for the given timeframe.

timeframe can be combined with single_file