Latch Interval (PI_PILA)
- Organization of this page
Function
The Latch Interval (PI_PILA) record stores performance data, taken at specific intervals, about latches. PFM - Agent for Oracle creates one record for each latch in an instance. This is a multi-instance record.
For the monitored Oracle version, if the data in the ADDR column in the Oracle static dictionary view V$LATCH is the same in every row, this record does not operate normally. To monitor latches in this case, use the Latch (PD_PDLA) record.
You can use the Oracle command sqlplus to check whether the data in the ADDR column is the same in every row. To do so, execute the following SQL statement:
SELECT ADDR FROM V$LATCH
For details about the sqlplus command, see the Oracle documentation.
- Notes
-
If the monitoring target is Oracle Database 12c Release 2 or later in a CDB configuration, this record includes latch information of monitoring PDB and common latch information for database instances.
Default and changeable values
|
Item |
Default value |
Changeable |
|---|---|---|
|
Collection Interval |
300 |
Y |
|
Collection Offset |
5 |
Y |
|
Log |
No |
Y |
|
LOGIF |
(Blank) |
Y |
|
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
PI_PILA_ADDR
Lifetime
From the creation to the deletion of an Oracle instance
Record size
-
Fixed part: 678 bytes
-
Variable part: 416 bytes
Fields
|
PFM - View name (PFM - Manager name) |
Description |
Summary |
Format |
Delta |
Supported version |
Data source |
|---|---|---|---|---|---|---|
|
Addr (ADDR) |
Latch address#1 |
COPY |
string(16) |
No |
All |
V$LATCH.ADDR |
|
Gets (GETS) |
Number of times latches were obtained for requests in the willingto-wait mode#2 |
AVG |
double |
Yes |
All |
V$LATCH.GETS |
|
Immediate Gets (IMMEDIATE_GETS) |
Number of times latches were obtained for requests in the no wait mode#2 |
AVG |
double |
Yes |
All |
V$LATCH.IMMEDIATE_GETS |
|
Immediate Hit % (IMMEDIATE_HIT_PERCENTAGE) |
Percentage of times that latches were obtained in the no wait mode (Rate at which latches were obtained in the first attempt) #2 |
AVG |
double |
No |
All |
(V$LATCH.IMMEDIATE_GETS/(V$LATCH.IMMEDIATE_GETS + V$LATCH.IMMEDIATE_MISSES)) * 100 |
|
Immediate Misses (IMMEDIATE_MISSES) |
Number of times latch acquisition failed for requests in the no wait mode#2 |
AVG |
double |
Yes |
All |
V$LATCH.IMMEDIATE_MISSES |
|
Latch # (LATCH_NUM) |
Latch number#1 |
COPY |
double |
No |
All |
V$LATCH.LATCH# |
|
Latch Name (NAME) |
Latch name#1 |
COPY |
string(50) |
No |
All |
V$LATCHNAME.NAME |
|
Level # (LEVEL_NUM) |
Latch level#1 |
COPY |
double |
No |
All |
V$LATCH.LEVEL# |
|
Misses (MISSES) |
Number of times the first attempt at latch acquisition failed for requests in the willingto-wait mode#2 |
AVG |
double |
Yes |
All |
V$LATCH.MISSES |
|
OS PID (OS_PID) |
OS's client process ID#1 |
COPY |
string(12) |
No |
All |
V$SESSION.PROCESS where V$LATCHHOLDER.SID = V$SESSION.SID |
|
OS User (OS_USER) |
OS's client user name#1 |
COPY |
string(30) |
No |
All |
V$SESSION.OSUSER where V$LATCHHOLDER.SID = V$SESSION.SID |
|
Oracle PID (PID) |
Process ID to which the latch belongs#1 |
COPY |
ulong |
No |
All |
V$LATCHHOLDER.PID |
|
Program (PROGRAM) |
Name of the program being executed#1 |
COPY |
string(48) |
No |
All |
V$SESSION.PROGRAM where V$LATCHHOLDER.SID = V$SESSION.SID |
|
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record#1 |
COPY |
time_t |
No |
All |
Agent Collector |
|
Record Type (INPUT_RECORD_TYPE) |
Record name (always PILA)#1 |
COPY |
string(4) |
No |
All |
Agent Collector |
|
SID (SID) |
Session ID to which the latch belongs#1 |
COPY |
ulong |
No |
All |
V$LATCHHOLDER.SID |
|
Sleeps (SLEEPS) |
Number of times the system slept when it needed to wait#2 |
AVG |
double |
Yes |
All |
V$LATCH.SLEEPS |
|
Spin Gets (SPIN_GETS) |
Number of latch requests that can wait that failed the first time but were successful during spinning#2 |
AVG |
double |
Yes |
All |
V$LATCH.SPIN_GETS |
|
Start Time (START_TIME) |
Collection start time for the performance data stored in the record#1 |
COPY |
time_t |
No |
All |
Agent Collector |
|
User (USERNAME) |
Oracle user name#1 |
COPY |
string(30) |
No |
All |
V$SESSION.USERNAME |
|
Waiters Woken (WAITERS_WOKEN) |
Number of times standby sleep was released#2 (always 0 for Oracle 10g Release 2 or later) |
AVG |
double |
Yes |
All |
V$LATCH.WAITERS_WOKEN |
|
Waits Holding Latch (WAITS_HOLDING_LATCH) |
Number of waits when other latches were held#2 (always 0 for Oracle 10g Release 2 or later) |
AVG |
double |
Yes |
All |
V$LATCH.WAITS_HOLDING_LATCH |
|
Willing To Wait Hit % (WILLING_TO_WAIT_HIT_PERCENTAGE) |
Percentage of times that latches were obtained in the willingto-wait mode (Rate at which latches were obtained in the first attempt) #2 |
AVG |
double |
No |
All |
((V$LATCH.GETS - V$LATCH.MISSES) / V$LATCH.GETS) * 100 |