Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/4471#discussion_r152825553
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/util/UpdatingPlanChecker.scala
---
@@ -116,14 +135,100 @@ object UpdatingPlanChecker {
val windowStartEnd = w.getWindowProperties.map(_.name)
// we have only a unique key if at least one window property is
selected
if (windowStartEnd.nonEmpty) {
- keys = Some(groupKeys ++ windowStartEnd)
+ val smallestAttribute = windowStartEnd.sorted.head
--- End diff --
Replace with `windowStartEnd.min`. Can you explain this logic? Selecting
only the first string looks a bit weird.
---
