Enabling SQL Trace in Oracle Database

The SQL Trace facility can either be enabled/disabled for an individual
session or the instance.
        *       To enable the SQL trace facility for your session
                issue the following SQL statement:
                      ALTER SESSION
                        SET SQL_TRACE = TRUE; 
        *       To disable the SQL trace facility for your session
                issue the following SQL statement:
                        ALTER SESSION

                        SET SQL_TRACE = FALSE;