DBA_HIST_LATCH_CHILDREN displays historical statistics about child latches. This view includes all columns of DBA_HIST_LATCH plus the CHILD# column. Note that child latches have the same parent if their LATCH# columns match each other. This view contains snapshots of V$LATCH_CHILDREN.

Column Datatype NULL Description
SNAP_ID NUMBER   Unique snapshot ID
DBID NUMBER   Database ID for the snapshot
INSTANCE_NUMBER NUMBER   Instance number for the snapshot
LATCH_NAME VARCHAR2(64)   Latch name
CHILD# NUMBER   Child latch number (unique only to each parent latch)
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)
SPIN_GETS NUMBER   Number of willing-to-wait latch requests which missed the first try but succeeded while spinning
SLEEP1 NUMBER   Waits that slept 1 time
SLEEP2 NUMBER   Waits that slept 2 times
SLEEP3 NUMBER   Waits that slept 3 times
SLEEP4 NUMBER   Waits that slept 4 or more times
WAIT_TIME NUMBER   Elapsed time spent waiting for the latch (in microseconds)