文档解释
ORA-29381: plan/consumer_group string referred to by another plan and cannot be deleted
Cause: An attempt was made to delete a plan or consumer group that is referred to by another plan.
Action: Remove all plan directives that have the plan or consumer group as GROUP_OR_SUBPLAN; then delete the plan or consumer group.
ORA-29381: 如果试图删除计划或消费者组，但是该计划/消费者组字符串被另一个计划引用，会出现ORA-29381错误。
官方解释
常见案例
一般处理方法及步骤
1、首先检查是否有其他计划引用该计划/消费者组。
2、如果是，请取消对它们的引用，然后重新运行删除命令。
3、如果不是，可能存在数据库内部错误。在这种情况下，请尝试使用exp/imp报告此错误并重新创建具有相同名称的计划或消费者组。
