User Trace

In order to trace all the actions by a specific user we can user below log on trigger:

CREATE OR REPLACE TRIGGER myuser_logon_trace
AFTER LOGON ON MYUSER.SCHEMA
BEGIN
execute immediate 'alter session set tracefile_identifier="MYUSER"';
DBMS_SESSION.SET_SQL_TRACE(TRUE);
END;
/

Now, we can find the output of the trace at "user_dump_dest" with "MYUSER" in the name.