Lock Waiters (PD_PDLW)
- Organization of this page
Function
The Lock Waiters (PD_PDLW) record stores performance data indicating the status (at a specific point in time) of all sessions waiting for lock and all sessions holding lock. PFM - Agent for Oracle creates one record for each lock that a session is waiting for. This is a multi-instance record.
If you cannot view the performance data in this record, create Oracle's static data dictionary view DBA_WAITERS. To create the static dictionary view DBA_WAITERS, you need to execute the CATBLOCK.SQL script that is provided by Oracle.
Default and changeable values
|
Item |
Default value |
Changeable |
|---|---|---|
|
Collection Interval |
600 |
Y |
|
Collection Offset |
60 |
Y |
|
Log |
No |
Y |
|
LOGIF |
(Blank) |
Y |
|
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
None
Lifetime
From the start to the end of a deadlock
Record size
-
Fixed part: 678 bytes
-
Variable part: 428 bytes
Fields
|
PFM - View name (PFM - Manager name) |
Description |
Summary |
Format |
Delta |
Supported version |
Data source |
|---|---|---|---|---|---|---|
|
Holding OS PID (HOLDING_PID) |
OS's client process ID corresponding to the session holding the lock |
-- |
string(30) |
No |
All |
V$SESSION.PROCESS |
|
Holding Session (HOLDING_SESSION) |
Session ID holding the lock |
-- |
ulong |
No |
All |
DBA_WAITERS.HOLDING_SESSION |
|
Holding User (HOLDING_USER) |
User name for the session holding the lock |
-- |
string(30) |
No |
All |
V$SESSION.USERNAME |
|
Lock ID1 (LOCK_ID1) |
Lock ID 1 |
-- |
string(40) |
No |
All |
DBA_WAITERS.LOCK_ID1 |
|
Lock ID2 (LOCK_ID2) |
Lock ID 2 |
-- |
string(40) |
No |
All |
DBA_WAITERS.LOCK_ID2 |
|
Lock Type (TYPE) |
Lock type |
-- |
string(30) |
No |
All |
DBA_WAITERS.TYPE |
|
Mode Held (MODE_HELD) |
Lock mode that was held during data collection |
-- |
string(40) |
No |
All |
DBA_WAITERS.MODE_HELD |
|
Mode Requested (MODE_REQUESTED) |
Lock mode that was requested during data collection |
-- |
string(40) |
No |
All |
DBA_WAITERS.MODE_REQUESTED |
|
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record |
-- |
time_t |
No |
All |
Agent Collector |
|
Record Type (INPUT_RECORD_TYPE) |
Record name (always PDLW) |
-- |
string(4) |
No |
All |
Agent Collector |
|
Start Time (START_TIME) |
Collection start time for the performance data stored in the record |
-- |
time_t |
No |
All |
Agent Collector |
|
Waiting OS PID (WAITING_PID) |
OS's client process ID corresponding to the session waiting for the lock |
-- |
string(30) |
No |
All |
V$SESSION.PROCESS |
|
Waiting Session (WAITING_SESSION) |
Session ID waiting for the lock |
-- |
ulong |
No |
All |
DBA_WAITERS.WAITING_SESSION |
|
Waiting User (WAITING_USER) |
User name for the session waiting for the lock |
-- |
string(30) |
No |
All |
V$SESSION.USERNAME |
|
XID (XID) |
ID used internally to identify the record |
-- |
string(100) |
No |
All |
DBA_WAITERS.LOCK_ID1 + DBA_WAITERS.LOCK_ID2 + DBA_WAITERS.HOLDING_SESSION + DBA_WAITERS.WAITING_SESSION |