> On Dec 11, 2023, at 6:40 AM, Mich Talebzadeh <mich.talebza...@gmail.com> > wrote: > > By default, the CBO is enabled in Spark.
Note that this is not correct. AQE is enabled <https://github.com/apache/spark/blob/8235f1d56bf232bb713fe24ff6f2ffdaf49d2fcc/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala#L664-L669> by default, but CBO isn’t <https://github.com/apache/spark/blob/8235f1d56bf232bb713fe24ff6f2ffdaf49d2fcc/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala#L2694-L2699>.