deterministic method describes whether this instance of the expression tree is deterministic, whereas Nondeterministic trait is about a class.
On Fri, Sep 23, 2016 at 10:46 AM, Jacek Laskowski <ja...@japila.pl> wrote: > 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 > >
