V$LATCHNAME displays information about decoded latch names for the latches shown in V$LATCH. The rows of V$LATCHNAME have a one-to-one correspondence to the rows of V$LATCH.
| Column | Datatype | Description |
| LATCH# | NUMBER | Latch number |
| NAME | VARCHAR2(64) | Latch name |
| HASH | NUMBER | Latch hash |
See Also:"V$LATCH"
V$LATCHHOLDER displays information about the current latch holders.
| Column | Datatype | Description |
| PID | NUMBER | Identifier of the process holding the latch |
| SID | NUMBER | Identifier of the session that owns the latch |
| LADDR | RAW(4 | 8) | Latch address |
| NAME | VARCHAR2(64) | Name of the latch being held |
| GETS | NUMBER | Number of times that the latch was obtained in either wait mode or no-wait mode |
V$LATCH_MISSES displays statistics about missed attempts to acquire a latch.
| Column | Datatype | Description |
| PARENT_NAME | VARCHAR2(64) | Latch name of a parent latch |
| WHERE | VARCHAR2(80) | This column is obsolete and maintained for backward compatibility. The value of this column is always equal to the value in LOCATION. |
| NWFAIL_COUNT | NUMBER | Number of times that no-wait acquisition of the latch failed |
| SLEEP_COUNT | NUMBER | Number of times that acquisition attempts caused sleeps |
| WTR_SLP_COUNT | NUMBER | Number of times a waiter slept |
| LONGHOLD_COUNT | NUMBER | Number of times someone held a latch for the entire duration of someone else's sleep |
| LOCATION | VARCHAR2(80) | Location that attempted to acquire the latch |
V$LATCH_CHILDREN displays statistics about child latches. This view includes all columns of V$LATCH plus the CHILD# column. Note that child latches have the same parent if their LATCH# columns match each other.
| Column | Datatype | Description |
| ADDR | RAW(4 | 8) | Address of the latch object |
| LATCH# | NUMBER | Latch number of the parent latch |
| CHILD# | NUMBER | Child latch number (unique only to each parent latch) |
| LEVEL# | NUMBER | Latch level |
| NAME | VARCHAR2(64) | Latch name |
| HASH | NUMBER | Latch hash |
| GETS | NUMBER | Number of times the latch was requested in willing-to-wait mode |
| MISSES | NUMBER | Number of times the latch was requested in willing-to-wait mode and the requestor had to wait |
| SLEEPS | NUMBER | Number of times a willing-to-wait latch request resulted in a session sleeping while waiting for the latch |
| IMMEDIATE_GETS | NUMBER | Number of times a latch was requested in no-wait mode |
| IMMEDIATE_MISSES | NUMBER | Number of times a no-wait latch request did not succeed (that is, missed) |
| WAITERS_WOKEN | NUMBER | This column has been deprecated and is present only for compatibility with previous releases of Oracle. No data is accumulated for this column; it will always have a value of zero. |
| WAITS_HOLDING_LATCH | NUMBER | This column has been deprecated and is present only for compatibility with previous releases of Oracle. No data is accumulated for this column; it will always have a value of zero. |
| SPIN_GETS | NUMBER | Willing-to-wait latch requests which missed the first try but succeeded while spinning |
| SLEEP[1 | 2 | 3 | 4] | NUMBER | These columns have been deprecated and are present only for compatibility with previous releases of Oracle. No data is accumulated for these columns; they will always have a value of zero. As a substitute for these columns you can query the appropriate rows of the V$EVENT_HISTOGRAM view where the EVENT column has a value of latch free or latch:%. |
| SLEEP[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. |
| WAIT_TIME | NUMBER | Elapsed time spent waiting for the latch (in microseconds) |
See Also: "V$LATCH"
