Script to check the name, version, instance, hostname

select '| Timestamp: '||to_char(systimestamp,'YYYY-MM-DD HH24:MI:SS TZH:TZM') from dual
union all
select '| Machine: '||host_name from v$instance
union all
select '| Version: '||version from v$instance
union all
select '| DBName: '||name from v$database
union all
select '| Instance: '||instance_name from v$instance

Check the startup time, instance name, host name, version, status of instance

set numwidth 5
column host_name format a20 tru
select inst_id, instance_name, host_name, version, status, startup_time
from gv$instance
order by inst_id;

Check wait event in RAC environment

WAITING SESSIONS:
— The entries that are shown at the top are the sessions that have
— waited the longest amount of time that are waiting for non-idle wait events

column state format a7 tru
column event format a25 tru
column last_sql format a40 tru
select sw.inst_id, sw.sid, sw.state, sw.event, sw.seconds_in_wait seconds,
sw.p1, sw.p2, sw.p3, sa.sql_text last_sql
from gv$session_wait sw, gv$session s, gv$sqlarea sa
where sw.event not in
('rdbms ipc message','smon timer','pmon timer',
'SQL*Net message from client','lock manager wait for remote message',
'ges remote message', 'gcs remote message', 'gcs for action', 'client message',
'pipe get', 'null event', 'PX Idle Wait', 'single-task message',
'PX Deq: Execution Msg', 'KXFQ: kxfqdeq - normal deqeue',
'listen endpoint status','slave wait','wakeup time manager')
and sw.seconds_in_wait > 0
and (sw.inst_id = s.inst_id and sw.sid = s.sid)
and (s.inst_id = sa.inst_id and s.sql_address = sa.address)
order by seconds desc;