Wait events talk about the running processes in the database. By analyzing wait events, you can identify bottlenecks in the database, determine the parameters that require tuning.
batched allocate scn lock request
BFILE check if exists
BFILE check if open
BFILE closure
BFILE get length
BFILE get name object
BFILE get path object
BFILE internal seek
BFILE open
BFILE read
broadcast mesg queue transition
broadcast mesg recovery queue transition
buffer busy waits
buffer deadlock
buffer for checkpoint
buffer latch
buffer read retry
checkpoint completed
cleanup of aborted processes
control file parallel write
control file sequential read
control file single write
cursor: mutex S
cursor: mutex X
cursor: pin S
cursor: pin S wait on X
cursor: pin X
Data Guard: process clean up
Data Guard: process exit
Data Guard Broker: single instance
db file parallel read
db file parallel write
db file scattered read
db file sequential read
db file single write
DFS db file lock
DFS lock handle
direct path read
direct path sync
direct path write
Disk file operations I/O
dispatcher shutdown
dispatcher timer
duplicate cluster key
enq: OW – initialization
enq: OW – termination
enqueue
flashback buf free by RVWR
flashback logfile sync
free buffer waits
free global transaction table entry
free process state object
gc recovery quiesce
GCS lock open S
GCS lock open X
gcs remastering wait for drop pkey
global cache busy
global cache lock cleanup
global cache freelist
inactive session
inactive transaction branch
index block split
instance state change
io done
kcl bg acks
ksxr wait for mount shared
ktm: instance recovery
latch activity
latch free
latch: cache buffers chains
library cache load lock
library cache lock
library cache pin
library cache shutdown
LMON global data update
lock manager wait for remote message
Log archive I/O
log buffer space
log file parallel write
log file sequential read
log file single write
log file switch (archiving needed)
log file switch (checkpoint incomplete)
log file switch (clearing log file)
log file switch (private strand flush incomplete)
log file switch completion
log file sync
log switch/archive
optimizer stats update retry
parallel recovery change buffer free
parallel recovery control message reply
parallel recovery coord send blocked
parallel recovery coord wait for reply
parallel recovery coordinator waits for slave cleanup
parallel recovery read buffer free
parallel recovery slave next change
pending global transaction(s)
pipe get
pipe put
PL/SQL lock timer
pmon timer
prewarm transfer retry
prior process spawner to be cleaned up
process startup
PX Deque wait
PX qref latch
PX server shutdown
PX signal server
rdbms ipc message
rdbms ipc message block
rdbms ipc reply
read by other session
recovery read
resmgr: become active
resmgr: cpu quantum
resmgr: pq queued
rolling migration: cluster quiesce
row cache lock
RVWR wait for flashback copy
sbtbufinfo
sbtgetbuf
sbtmapbuf
sbtrelbuf
scginq AST call
SGA: allocation forcing component growth
SGA: MMAN sleep for component shrink
SGA: sga_target resize
Shared IO Pool Memory
single-task message
shared server idle wait
smon timer
SQL*Net break/reset to client
SQL*Net break/reset to dblink
SQL*Net message from client
SQL*Net message from dblink
SQL*Net message to client
SQL*Net message to dblink
SQL*Net more data from client
SQL*Net more data from dblink
SQL*Net more data to client
SQL*Net more data to dblink
Streams AQ: waiting for messages in the queue
switch logfile command
TCP Socket (KGAS)
timer in sksawat
transaction
unbound tx
undo_retention publish retry
undo segment extension
undo segment recovery
undo segment tx slot
virtual circuit status
virtual circuit wait
WCR: replay client notify
WCR: replay clock
WCR: replay lock order
WCR: replay paused
WCR: Sync context busy
WMON goes to sleep
write complete waits
writes stopped by instance recovery or database suspension