V$MUTEX_SLEEP_HISTORY

V$MUTEX_SLEEP_HISTORY displays time-series data. Each row in this view is for a specific time, mutex type, location, requesting session and blocking session combination. That is, it shows data related to a specific session (requesting session) that slept while requesting a specific mutex type and location, because it was being held by a specific blocking session. The data in this view is contained within a circular buffer, with the most recent sleeps shown.

Column	Datatype	Description
`MUTEX_IDENTIFIER`	`NUMBER`	Mutex ID
`SLEEP_TIMESTAMP`	`TIMESTAMP(6)`	The last date/time this `MUTEX_TYPE` and `LOCATION` was slept for by the `REQUESTING_SESSION`, while being held by the `BLOCKING_SESSION`.
`MUTEX_TYPE`	`VARCHAR2(32)`	Type of action/object the mutex protects
`GETS`	`NUMBER`	The number of times the mutex/location was requested by the requesting session while being held by the blocking session. `GETS` is only incremented once per request, irrespective of the number of sleeps required to obtain the mutex.
`SLEEPS`	`NUMBER`	The number of times the requestor had to sleep before obtaining the mutex
`REQUESTING_SESSION`	`NUMBER`	The SID of a session requesting the mutex
`BLOCKING_SESSION`	`NUMBER`	The SID of a session holding the mutex
`LOCATION`	`VARCHAR2(40)`	The code location where the waiter slept for the mutex
`MUTEX_VALUE`	`RAW(4)`	If the mutex is held in exclusive (X) mode, this column shows the SID of the blocking session, else it shows the number of sessions referencing the mutex in S mode.
`P1`	`NUMBER`	Reserved for internal use
`P1RAW`	`RAW(4)`	Reserved for internal use
`P2`	`NUMBER`	Reserved for internal use
`P3`	`NUMBER`	Reserved for internal use
`P4`	`NUMBER`	Reserved for internal use
`P5`	`VARCHAR2(64)`	Reserved for internal use