Lock Waiters (PD_PDLW)
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 - RM 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 |
ODBC key fields
None
Lifetime
From the start to the end of a deadlock
Record size
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 | Remote Monitor Collector |
Record Type (INPUT_RECORD_TYPE) | Record name (always PDLW) | -- | string(4) | No | All | Remote Monitor Collector |
Start Time (START_TIME) | Collection start time for the performance data stored in the record | -- | time_t | No | All | Remote Monitor Collector |
VA DeviceID (VADEVICEID) | Device ID of virtual agent. | -- | string(256) | No | All | Remote Monitor 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.WAITING_SESSION + DBA_WAITERS.HOLDING_SESSION + DBA_WAITERS.LOCK_ID1 + DBA_WAITERS.LOCK_ID2 |