Github user viirya commented on a diff in the pull request:

    https://github.com/apache/spark/pull/18652#discussion_r127895248
  
    --- Diff: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
 ---
    @@ -1912,6 +1913,26 @@ class Analyzer(
               nondeterToAttr.get(e).map(_.toAttribute).getOrElse(e)
             }.copy(child = newChild)
     
    +      case j: Join if j.condition.isDefined && 
!j.condition.get.deterministic =>
    +        j match {
    +          // We can push down non-deterministic joining keys.
    +          // We can't push down non-deterministic conditions.
    +          case ExtractEquiJoinKeys(_, leftKeys, rightKeys, conditions, _, 
_)
    --- End diff --
    
    Joining keys can only be equi-join. It is exactly the use case discussed in 
the dev mailling list. It's actually useful for the use cases.
    
    A general non-deterministic join condition pushdown doesn't make a lot of 
sense. The kind of predicates like `rand(1) > 0 && rand(11) < 0` can be a 
serious concern. The join results can be different before and after pushdown.



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