V$LATCH

V$LATCH shows aggregate latch statistics for both parent and child latches, grouped by latch name. Individual parent and child latch statistics are broken down in the views V$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(50)`	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`	For some latches, the session releasing the latch posts a session waiting for the latch. This counts the number of times a waiting session was awakened.
`WAITS_HOLDING_LATCH`	`NUMBER`	Number of waits for the latch while the waiter was holding a different latch
`SPIN_GETS`	`NUMBER`	Willing-to-wait latch requests which missed the first try but succeeded while spinning
`SLEEP[1 \| 2 \| 3]`	`NUMBER`	Waits that slept 1 time through 3 times, respectively
`SLEEP4`	`NUMBER`	Waits that slept 4 or more times
`SLEEP[5 \| 6 \| 7 \| 8 \| 9 \| 10 \| 11]`	`NUMBER`	These columns are present for compatibility with previous releases of Oracle. No data is accumulated for these columns.
`WAIT_TIME`	`NUMBER`	Elapsed time spent waiting for the latch (in microseconds)

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