dle wait class events 经常出现，但是不表示有任何问题
以下为空闲等待类事件
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
sql> select name from v$event_name where wait_class#=6
NAME
----------------------------------------------------------------
pmon timer
VKTM Logical Idle Wait
VKTM Init Wait for GSGA
IORM Scheduler Slave Idle Wait
rdbms ipc message
i/o slave wait
VKRM Idle
wait for unread message on broadcast channel
wait for unread message on multiple broadcast channels
class slave wait
KSV master wait
NAME
----------------------------------------------------------------
PING
watchdog main loop
DIAG idle wait
ges remote message
gcs remote message
heartbeat monitor sleep
SGA: MMAN sleep for component shrink
MRP redo arrival
LNS ASYNC archive log
LNS ASYNC dest activation
LNS ASYNC end of log
NAME
----------------------------------------------------------------
simulated log write delay
LGWR real time apply sync
parallel recovery slave idle wait
LogMiner builder: idle
LogMiner builder: branch
LogMiner preparer: idle
LogMiner reader: log (idle)
LogMiner reader: redo (idle)
LogMiner client: transaction
LogMiner: other
LogMiner: activate
NAME
----------------------------------------------------------------
LogMiner: reset
LogMiner: find session
LogMiner: internal
Logical Standby Apply Delay
parallel recovery coordinator waits for slave cleanup
parallel recovery control message reply
parallel recovery slave next change
PX Deq: Txn Recovery Start
PX Deq: Txn Recovery Reply
fbar timer
smon timer
NAME
----------------------------------------------------------------
PX Deq: Metadata Update
Space Manager: slave idle wait
PX Deq: Index Merge Reply
PX Deq: Index Merge Execute
PX Deq: Index Merge Close
PX Deq: kdcph_mai
PX Deq: kdcphc_ack
shared server idle wait
dispatcher timer
cmon timer
pool server timer
NAME
----------------------------------------------------------------
JOX Jit Process Sleep
jobq slave wait
pipe get
PX Deque wait
PX Idle Wait
PX Deq: Join ACK
PX Deq Credit: need buffer
PX Deq Credit: send blkd
PX Deq: Msg Fragment
PX Deq: Parse Reply
PX Deq: Execute Reply
NAME
----------------------------------------------------------------
PX Deq: Execution Msg
PX Deq: Table Q Normal
PX Deq: Table Q Sample
Streams fetch slave: waiting for txns
Streams: waiting for messages
Streams capture: waiting for archive log
single-task message
SQL*Net message from client
SQL*Net vector message from client
SQL*Net vector message from dblink
PL/SQL lock timer
NAME
----------------------------------------------------------------
Streams AQ: emn coordinator idle wait
EMON slave idle wait
Streams AQ: waiting for messages in the queue
Streams AQ: waiting for time management or cleanup tasks
Streams AQ: delete acknowledged messages
Streams AQ: deallocate messages from Streams Pool
Streams AQ: qmn coordinator idle wait
Streams AQ: qmn slave idle wait
Streams AQ: RAC qmn coordinator idle wait
HS message to agent
ASM background timer
NAME
----------------------------------------------------------------
auto-sqltune: wait graph update
WCR: replay client notify
WCR: replay clock
WCR: replay paused
JS external job
cell worker idle
94 rows selected.
SQL>