UPTIME

Calcular Disponibilidad

select
   'Hostname : ' || host_name
   ,'Instance Name : ' || instance_name
   ,'Started At : ' || to_char(startup_time,'DD-MON-YYYY HH24:MI:SS') stime
   ,'Uptime : ' || floor(sysdate - startup_time) || ' days(s) ' ||
   trunc( 24*((sysdate-startup_time) -
   trunc(sysdate-startup_time))) || ' hour(s) ' ||
   mod(trunc(1440*((sysdate-startup_time) -
   trunc(sysdate-startup_time))), 60) ||' minute(s) ' ||
   mod(trunc(86400*((sysdate-startup_time) -
   trunc(sysdate-startup_time))), 60) ||' seconds' uptime
from
   sys.v_$instance; If you assume that PMON startup time is the same as the database startup time, you can get the uptime here:select
   to_char(logon_time,'DD/MM/YYYY HH24:MI:SS')
from
   v$session
where
   sid=1;