截止到spark 2.0,spark-sql的优化器永远只会返回一个plan

[liprais]

据源代码所示，spark-sql的优化器永远只会返回一个plan，也就是说目前spark-sql只有逻辑优化，没有物理优化

[liprais]

https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/planning/QueryPlanner.scala