Hi Herman, That helps to know that someone can explain why we've got the two nondeterministic states.
It's not possible to say...a non-Nondeterministic expression can be non-deterministic (the former is the trait while the latter is the method) #strange Pozdrawiam, Jacek Laskowski ---- https://medium.com/@jaceklaskowski/ Mastering Apache Spark 2.0 http://bit.ly/mastering-apache-spark Follow me at https://twitter.com/jaceklaskowski On Fri, Sep 23, 2016 at 6:44 PM, Herman van Hövell tot Westerflier <hvanhov...@databricks.com> wrote: > Jacek, > > A non-deterministic expression usually holds some state. The > Nondeterministic trait makes sure a user can initialize this state properly. > Take a look at InterpretedProjection for instance. > > HTH > > -Herman > > On Fri, Sep 23, 2016 at 8:28 AM, Jacek Laskowski <ja...@japila.pl> wrote: >> >> Hi, >> >> Just came across the Expression trait [1] that can be check for >> determinism by the method deterministic [2] and trait Nondeterministic >> [3]. Why both? >> >> [1] >> https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala#L53 >> [2] >> https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala#L80 >> [3] >> https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala#L271 >> >> Pozdrawiam, >> Jacek Laskowski >> ---- >> https://medium.com/@jaceklaskowski/ >> Mastering Apache Spark 2.0 http://bit.ly/mastering-apache-spark >> Follow me at https://twitter.com/jaceklaskowski >> >> --------------------------------------------------------------------- >> To unsubscribe e-mail: dev-unsubscr...@spark.apache.org >> > --------------------------------------------------------------------- To unsubscribe e-mail: dev-unsubscr...@spark.apache.org
