awsdms_txn_state-重复键值违反了唯一约束“ awsdms_txn_state_task_recovery_index”

Question

我已经从Oracle到Postgres建立了AWS DMS CDC任务。选中创建恢复表复选框，并且我在设置文件中有Users +----+------+ | Id | Name | +----+------+ | 1 | John | +----+------+ Subscriptions +----+--------+-----------+ | Id | userId | data | +----+--------+-----------+ | 1 | 1 | some data | +----+--------+-----------+ | 2 | 1 | some data | +----+--------+-----------+ Payments +----+----------------+--------+ | Id | subscriptionId | amount | +----+----------------+--------+ | 1 | 1 | 30 | +----+----------------+--------+ | 2 | 2 | 50 | +----+----------------+--------+

它通过以下设置在目标数据库上创建"TaskRecoveryTableEnabled": true表

awsdms_txn_state

请注意，存在some_user@db => \d awsdms_txn_state Table "some_user.awsdms_txn_state" Column | Type | Collation | Nullable | Default -------------+-----------------------------+-----------+----------+--------- SERVER_NAME | character varying(384) | | not null | TASK_NAME | character varying(384) | | not null | STATE_TIME | timestamp without time zone | | not null | CHECKPOINT | character varying(3072) | | not null | Indexes: "awsdms_txn_state_task_recovery_index" UNIQUE, btree ("SERVER_NAME", "TASK_NAME") 个唯一索引

现在，在CDC任务运行期间，它连续失败并出现以下错误：

awsdms_txn_state_task_recovery_index

原因显而易见。它尝试将记录插入到该表中，而该记录在此英国索引上失败

删除索引可以“解决”问题，并开始向该表添加新行

[TARGET_APPLY ]E: Failed to execute statement: '' [1022502] (ar_odbc_stmt.c:2478)
[TARGET_APPLY ]E: RetCode: SQL_ERROR SqlState: 23505 NativeError: 1 Message: ERROR: duplicate key value violates unique constraint "awsdms_txn_state_task_recovery_index";, Error while executing the query [1022510] (ar_odbc_stmt.c:2484)
[TARGET_APPLY ]E: Error executing command [1022502] (streamcomponent.c:1676)

问题：
some_user@db => select * from awsdms_txn_state; SERVER_NAME | TASK_NAME | STATE_TIME | CHECKPOINT -----------------------+----------------------------+---------------------+-------------------------------------------------------------------------------------------------- localhost.localdomain | NM6KQWHZQL5RLONADKKONM5MCA | 2019-01-28 15:44:48 | checkpoint:V1#318064#0000002D0ABC5EB5010000010001458E00099A29016C00000000002D0ABC5D2B#0#0#*#0#73 some_user@db => drop index awsdms_txn_state_task_recovery_index; DROP INDEX some_user@db => \d awsdms_txn_state Table "some_user.awsdms_txn_state" Column | Type | Collation | Nullable | Default -------------+-----------------------------+-----------+----------+--------- SERVER_NAME | character varying(384) | | not null | TASK_NAME | character varying(384) | | not null | STATE_TIME | timestamp without time zone | | not null | CHECKPOINT | character varying(3072) | | not null | some_user@db => select * from awsdms_txn_state; SERVER_NAME | TASK_NAME | STATE_TIME | CHECKPOINT -----------------------+----------------------------+---------------------+-------------------------------------------------------------------------------------------------- localhost.localdomain | NM6KQWHZQL5RLONADKKONM5MCA | 2019-01-28 15:44:48 | checkpoint:V1#318064#0000002D0ABC5EB5010000010001458E00099A29016C00000000002D0ABC5D2B#0#0#*#0#73 localhost.localdomain | NM6KQWHZQL5RLONADKKONM5MCA | 2019-02-05 11:24:02 | localhost.localdomain | NM6KQWHZQL5RLONADKKONM5MCA | 2019-02-05 11:24:09 | (3 rows) 表的正确状态是什么？
它是否应该始终包含单个记录，而CDC现在有一个试图插入新行而不是UPDATE的错误？

还是表ddl中存在错误，并且不应定义任何唯一索引？