Collect user session statistics:

That is, get the most complete report on what actions the user performed and how the database responded to these actions.

Show current sessions

select t.SID, t.SERIAL#, t.osuser as "User", t.MACHINE as "Computer", t.PROGRAM as "Program"
from v$session t
--where (NLS_LOWER(t.PROGRAM) = 'myprogram.exe') -- view sessions from myprogram.exe
--where status='ACTIVE' and osuser!='SYSTEM' -- view user sessions
order by 4 asc;

Enable tracing

begin
dbms_system.set_sql_trace_in_session(sid => 139 , serial# => 40063, sql_trace => true);
end;

Disable tracing

begin
dbms_system.set_sql_trace_in_session(sid => 139 , serial# => 40063, sql_trace => false);
end;

Convert the trace file into a human-readable format.

CMD> tkprof filename.trc filename.txt