Oracle中start with…connect by prior怎么优化?
一个地址表一共有8级地址,传入地址id,查询所有上级地址,代码为:
select address_id addressId,
address_name addressName,
address_level addressLevel
from rm_address t
start with t.address_id = #villageId#
connect by t.address_id = PRIOR t.PARENT_ADDRESS_ID
order by address_level
现在查询很慢,求问怎么优化?## 标题文字 ##
此类问题,建议先说一下表的数据量,索引情况,以及目前sql语句的执行时间、执行计划,以方便大家分析问题。
按照你写的sql语句,请先检查t.address_id字段上是否有索引。