oradebug wakeup

Waking up SMON

Typically, the backround process development/databases/Oracle/architecture/processes/background/SMON sleeps for 5 minutes between its activities.

With oradebug wakup, it can be woken up at anytime.

First, we need to determine the PID of SMON with the following query (which conveniently also returns how long the SMON process was already sleeping and how long it is expected to sleep):

select
   p.pid,
   s.state,
   s.event,      
   to_char(s.wait_time_micro      / 1000 / 1000, '999,990.000') wait_time,
   to_char(s.time_remaining_micro / 1000 / 1000, '999,990.000') time_remaining
from
   v$process   p                        join
   v$bgprocess b on p.addr = b.paddr    join
   v$session   s on p.addr = s.paddr
where
   b.name='SMON';

With this PID, we can now wake up SMON:

oradebug wakeup 24

After executing this command, the previous query should now show a low wait_time.