Init.ora

Show non-default parameters

set pages 100 set lines 100 select name ||'='||decode(type, 2, **')||value||decode(type, 2, **') parameter from v$parameter where 1=1 and isdefault = 'FALSE' and value is not null order by name;

Reset/Unset a spfile parameter

 alter system reset <parameter> scope=spfile sid='*'