Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3673#discussion_r115729740
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/MapJoinLeftRunner.scala
---
@@ -31,7 +32,19 @@ class MapJoinLeftRunner[IN1, IN2, OUT](
override def flatMap(multiInput: IN1, out: Collector[OUT]): Unit = {
broadcastSet match {
case Some(singleInput) => function.join(multiInput, singleInput, out)
- case None =>
+ case None => {
--- End diff --
A `MatchError` is thrown when no suitable pattern is found (Akka uses a lot
of pattern matching, that's probably why you found that error, but it's actual
a Scala thing).
This means that there is the case of an empty `singleElement` in case of an
inner join. The problem can be easily solved by not replacing `case None =>`
with `case None if outerJoin =>` but just inserting `case None if outerJoin =>
` in between. Pattern matching works from top to bottom and takes the first
match (following matches are not executed).
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