Note
This view is available starting with V4.2.0.
Purpose
This view displays the history of all executed Transfer tasks in the current tenant.
Columns
Column |
Type |
Nullable |
Description |
|---|---|---|---|
| TASK_ID | NUMBER(38) | NO | The ID of the Transfer task. |
| CREATE_TIME | TIMESTAMP(6) WITH LOCAL TIME ZONE | NO | The time when the task was started. |
| MODIFY_TIME | TIMESTAMP(6) WITH LOCAL TIME ZONE | NO | The time when the task was completed, including the time when it was canceled. |
| SRC_LS | NUMBER(38) | NO | The source log stream (the log data stream generated by the data source). |
| DEST_LS | NUMBER(38) | NO | The destination log stream. |
| PART_LIST | CLOB | YES | The list of partitions, including user table partitions and global index partitions. |
| PART_COUNT | NUMBER(38) | YES | The number of partitions in the partition list. |
| NOT_EXIST_PART_LIST | CLOB | YES | The list of partitions that were planned to be executed in this task but did not exist when the lock was acquired. |
| LOCK_CONFLICT_PART_LIST | CLOB | YES | The list of partitions that were planned to be executed in this task but encountered a lock conflict when the lock was acquired. |
| TABLE_LOCK_TABLET_LIST | CLOB | YES | The list of tablets of partition-level table locks successfully acquired when the task entered the START state. This list is used for table lock migration. It contains only the tablets corresponding to the partitions in the PART_LIST. |
| TABLET_LIST | CLOB | YES | The complete list of tablets involved in the Transfer operation. This list includes not only the tablets listed in the PART_LIST but also those associated with local index tables and LOB auxiliary tables. |
| TABLET_COUNT | NUMBER(38) | YES | The number of tablets in the tablet list. |
| START_SCN | NUMBER(38) | YES | The SCN when the Transfer operation was initiated. |
| FINISH_SCN | NUMBER(38) | YES | The SCN when the Transfer operation was completed. |
| STATUS | VARCHAR2(64) | NO | The status of the task. Valid values:
|
| TRACE_ID | VARCHAR2(64) | NO | The trace ID of the entire task. |
| RESULT | NUMBER(38) | YES | The result of the task. |
| BALANCE_TASK_ID | NUMBER(38) | NO | The ID of the associated load balancing task. This Transfer task is a subtask generated by the corresponding load balancing task. |
| TABLE_LOCK_OWNER_ID | NUMBER(38) | YES | When a table lock is acquired, the system generates an owner_id for each table lock to identify the owner of the lock. When releasing the lock, the corresponding owner_id must be provided to ensure the system can correctly identify and release the lock. |
| COMMENT | CLOB | YES | The comment. This column records the reason for the task being stuck, diagnostic information, and the failure details of the task. |
Sample query
Query the history of all executed Transfer tasks in the current tenant.
obclient[SYS]> SELECT * FROM SYS.DBA_OB_TRANSFER_TASK_HISTORY\G
The query result is as follows:
*************************** 1. row ***************************
TASK_ID: 1
CREATE_TIME: 09-MAY-25 02.45.18.643425 PM
FINISH_TIME: 09-MAY-25 02.45.23.079501 PM
SRC_LS: 1001
DEST_LS: 1002
PART_LIST: 500002:500011,500002:500012,500002:500013,500002:500014,500002:500015,500002:500016
PART_COUNT: 6
NOT_EXIST_PART_LIST: NULL
LOCK_CONFLICT_PART_LIST: NULL
TABLE_LOCK_TABLET_LIST: 200008,200009,200010,200011,200012,200013
TABLET_LIST: 200008:0,200009:0,200010:0,200011:0,200012:0,200013:0
TABLET_COUNT: 6
START_SCN: 1746773121749985001
FINISH_SCN: 1746773122896124001
STATUS: COMPLETED
TRACE_ID: YB4*************************-0-0
RESULT: 0
BALANCE_TASK_ID: 321373
TABLE_LOCK_OWNER_ID: 321425
COMMENT: NULL
1 row in set
References
Query the list of Tablet-level load balancing tasks (Task) in the current tenant: DBA_OB_TRANSFER_TASKS
Query the list of log stream-level load balancing jobs (Job) in the current tenant:
Query the list of log stream-level load balancing tasks (Task) in the current tenant:
Query the list of Transfer partition tasks (Task) in the current tenant:
For more information about data load balancing, see Data load balancing.