Note
This view is available starting with V4.2.0.
Purpose
This view displays the Transfer tasks that are currently being executed in the current tenant. Multiple load balancing tasks can be executed at the same time, and all these tasks (TRANSFER_TASK) belong to the same load balancing job (BALANCE_JOB).
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 created. |
| MODIFY_TIME | TIMESTAMP(6) WITH LOCAL TIME ZONE | NO | The time when the information was last updated. |
| SRC_LS | NUMBER(38) | NO | The source log stream (the log data stream generated from 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 lock conflicts when the lock was acquired. |
| TABLE_LOCK_TABLET_LIST | CLOB | YES | The list of tablets that were successfully locked at the partition level when the task entered the START state. This list is used for table lock migration. It only contains tablets corresponding to partitions in the PART_LIST. |
| TABLET_LIST | CLOB | YES | The complete list of tablets involved in this Transfer operation. It includes not only the tablets listed in the PART_LIST but also tablets 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 task was initiated. |
| FINISH_SCN | NUMBER(38) | YES | The SCN when the Transfer task 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 table lock, the corresponding owner_id must be provided so that the system can correctly identify and release the lock. |
| COMMENT | CLOB | YES | The comment. It records the reason for the task being stuck, diagnostic information, and the failure status of the task. |
Sample query
Query the Transfer tasks that are currently being executed in the current tenant.
obclient [SYS]> SELECT * FROM SYS.DBA_OB_TRANSFER_TASKS\G
The query result is as follows:
*************************** 1. row ***************************
TASK_ID: 1
CREATE_TIME: 09-MAY-25 02.45.18.643425 PM
MODIFY_TIME: 09-MAY-25 02.45.22.093721 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: 0
STATUS: DOING
TRACE_ID: YB4*******************************************-0-0
RESULT: 0
BALANCE_TASK_ID: 321373
TABLE_LOCK_OWNER_ID: 321425
COMMENT: NULL
1 row in set
References
To view the history of tablet-level load balancing tasks in the current tenant, see DBA_OB_TRANSFER_TASK_HISTORY.
To view the log stream-level load balancing jobs in the current tenant, see:
To view the log stream-level load balancing tasks in the current tenant, see:
To view the transfer partition tasks in the current tenant, see:
For more information about data load balancing, see Data load balancing.