fixup

apache · Jan 19, 2024 · 43fb07b · 43fb07b
1 parent 2607ff6
commit 43fb07b
Showing 1 changed file with 9 additions and 4 deletions.
diff --git a/backends-velox/src/main/scala/org/apache/spark/sql/catalyst/FlushableHashAggregateRule.scala b/backends-velox/src/main/scala/org/apache/spark/sql/catalyst/FlushableHashAggregateRule.scala
@@ -113,11 +113,16 @@ object FlushableHashAggregateRule {
    * perform optimizations like doing "partial_count(a, b, c)" directly on the output data.
    */
   def isAggInputAlreadyDistributedWithAggKeys(agg: HashAggregateExecTransformer): Boolean = {
-    val distribution = if (agg.groupingExpressions.isEmpty) {
-      UnspecifiedDistribution
-    } else {
-      ClusteredDistribution(agg.groupingExpressions)
+    if (agg.groupingExpressions.isEmpty) {
+      // Empty grouping set () should not be satisfied by any partitioning patterns.
+      //   E.g.,
+      //   (a, b) satisfies (a, b, c)
+      //   (a, b) satisfies (a, b)
+      //   (a, b) doesn't satisfy (a)
+      //   (a, b) doesn't satisfy ()
+      return false
     }
+    val distribution = ClusteredDistribution(agg.groupingExpressions)
     agg.child.outputPartitioning.satisfies(distribution)
   }
 }