ORA-12838: cannot read/modify an object after modifying it in parallel

以上代码引起了以下错误：

ORA-12838: cannot read/modify an object after modifying it in parallel

12838. 00000 - "cannot read/modify an object after modifying it in parallel"

*Cause: Within the same transaction, an attempt was made to add read or modification statements on a table after it had been modified in parallel or with direct load. This is not permitted.

*Action: Rewrite the transaction, or break it up into two transactions one containing the initial modification and the second containing the parallel modification operation.

insert /*+ append */ into table 操作对于这个表的锁级为6，而insert 操作对这个锁级为3 ，在同一session下，执行了上面这个操作，没有提交/回滚事务，然后有对table进行select或update,delete,insert操作就会报上面的错误。