Clarify global aggregation in applyAggregation

It was found to be confusing.
trinodb · Oct 18, 2023 · 8b9f55e · 8b9f55e
1 parent 8400452
commit 8b9f55e
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/core/trino-spi/src/main/java/io/trino/spi/connector/ConnectorMetadata.java b/core/trino-spi/src/main/java/io/trino/spi/connector/ConnectorMetadata.java
@@ -1405,6 +1405,11 @@ default Optional<AggregationApplicationResult<ConnectorTableHandle>> applyAggreg
             Map<String, ColumnHandle> assignments,
             List<List<ColumnHandle>> groupingSets)
     {
+        // Global aggregation is represented by [[]]
+        if (groupingSets.isEmpty()) {
+            throw new IllegalArgumentException("No grouping sets provided");
+        }
+
         return Optional.empty();
     }