Question: I need to get the
resource manager wait event's description. I use Resource
Manager in one of my databases and I can't to find the wait
event's description. I know of only 'resmgr: become active'
resource manager wait event.Answer:
The Oracle docs note two main wait events associated with
the Oracle resource manager, both visible in v$session.
- resmgr: become active:
This indicates a real performance issue. The session
is waiting for a resource manager active session slot. The
'resmgr: become active' event happens when the
resource manager is enabled and the number of active
sessions in the session's current consumer group exceeds the
current resource plan's active session limit for the users
consumer group. To reduce the occurrence of the
'resmgr: become active' wait event, you
increase the active session limit for the offending
session's current consumer group.
- resmgr:
cpu quantum: This is just a notification that
sessions are sharing CPU, not necessarily a performance
problem. The session is waiting to be allocated a
quantum of cpu. This event occurs when the resource manager
is enabled and is throttling CPU consumption. To reduce the
occurrence of this wait event, increase the CPU allocation
for the session's current consumer group.
This example script will count the occurrences of
resource manager waits.
For full scripts, see the
Oracle Script
collection download.
select
event,
count(*)
from
v$session
where
event like "resmgr%'
group by
event
having
count(*) > 10
order by
2 desc ;
