Using the example below one can include instance name in the spool filename when using SQL*Plus

SQL> set termout off
SQL> set feedback off
SQL> undefine curdate dcol
SQL> column dcol new_value curdate noprint
SQL> column dbcol new_value db noprint

SQL> select sys_context(#&39;userenv#&39;,#&39;db_name#&39;) dbcol, to_char(sysdate,#&39;YYYYMMDD_HH24MISS#&39;) dcol from dual;

SQL> set termout on
SQL> set feedback on

SQL> spool &db._&curdate._spool.txt

…
SQL> spool off