V$LATCH

V$LATCH displays aggregate latch statistics for both parent and child latches, grouped by latch name. Individual parent and child latch statistics are broken down in the views V$LATCH_PARENT and V$LATCH_CHILDREN.

Column	Datatype	Description
`ADDR`	`RAW(4 \| 8)`	Address of the latch object
`LATCH#`	`NUMBER`	Latch number
`LEVEL#`	`NUMBER`	Latch level
`NAME`	`VARCHAR2(64)`	Latch name
`HASH`	`NUMBER`	Latch hash
`GETS`	`NUMBER`	Number of times the latch was requested in willing-to-wait mode
`MISSES`	`NUMBER`	Number of times the latch was requested in willing-to-wait mode and the requestor had to wait
`SLEEPS`	`NUMBER`	Number of times a willing-to-wait latch request resulted in a session sleeping while waiting for the latch
`IMMEDIATE_GETS`	`NUMBER`	Number of times a latch was requested in no-wait mode
`IMMEDIATE_MISSES`	`NUMBER`	Number of times a no-wait latch request did not succeed (that is, missed)
`WAITERS_WOKEN`	`NUMBER`	This column has been deprecated and is present only for compatibility with previous releases of Oracle. No data is accumulated for this column; it will always have a value of zero.
`WAITS_HOLDING_LATCH`	`NUMBER`	This column has been deprecated and is present only for compatibility with previous releases of Oracle. No data is accumulated for this column; it will always have a value of zero.
`SPIN_GETS`	`NUMBER`	Willing-to-wait latch requests which missed the first try but succeeded while spinning
`SLEEP[1 \| 2 \| 3 \| 4 \| 5 \| 6 \| 7 \| 8 \| 9 \| 10 \| 11]`	`NUMBER`	These columns have been deprecated and are present only for compatibility with previous releases of Oracle. No data is accumulated for these columns; they will always have a value of zero. As a substitute for these columns you can query the appropriate rows of the `V$EVENT_HISTOGRAM` view where the `EVENT` column has a value of `latch free` or `latch:%`.
`WAIT_TIME`	`NUMBER`	Elapsed time spent waiting for the latch (in microseconds)