V$LATCH_CHILDREN
displays statistics about child latches. This view includes all columns of V$LATCH
plus the CHILD#
column. Note that child latches have the same parent if their LATCH#
columns match each other.
Column | Datatype | Description |
---|---|---|
ADDR |
RAW(4 | 8) |
Address of the latch object |
LATCH# |
NUMBER |
Latch number of the parent latch |
CHILD# |
NUMBER |
Child latch number (unique only to each parent latch) |
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$EVENT_HISTOGRAM view where the EVENT column has a value of latch free or latch:% . |
WAIT_TIME |
NUMBER |
Elapsed time spent waiting for the latch (in microseconds) |
See Also:
"V$LATCH"