ORA-12838

11.2.0.4

direct path insert 

■ If any serial or parallel statement attemptsto access a table that has alreadyQueries that access the same table, partition, or index are allowed before the 

direct-path INSERTstatement, but not after it.

这里说的在direct path insert后会出错，是在同一个session里面insert append后还未commit时会出现；

如果已经commit后或者是在别的session里面查询该表不会出现此错误