fix(isthmus): fix tpcds query 67

Author: ZorinAnton

core/src/main/java/io/substrait/relation/Aggregate.java

@@ -21,17 +21,24 @@ public abstract class Aggregate extends SingleInputRel implements HasExtension {
 
   @Override
   protected Type.Struct deriveRecordType() {
-    return TypeCreator.REQUIRED.struct(
-        Stream.concat(
-            // unique grouping expressions
-            getGroupings().stream()
-                .flatMap(g -> g.getExpressions().stream())
-                .collect(Collectors.toCollection(LinkedHashSet::new))
-                .stream()
-                .map(Expression::getType),
+    boolean isGroupingSet = getGroupings().size() > 1;
 
-            // measures
-            getMeasures().stream().map(t -> t.getFunction().getType())));
+    Stream<Type> groupingTypes =
+        getGroupings().stream()
+            .flatMap(g -> g.getExpressions().stream())
+            .collect(Collectors.toCollection(LinkedHashSet::new))
+            .stream()
+            .map(
+                expr -> {
+                  if (isGroupingSet) {
+                    return TypeCreator.asNullable(expr.getType());
+                  }
+                  return expr.getType();
+                });
+
+    Stream<Type> measureTypes = getMeasures().stream().map(t -> t.getFunction().getType());
+
+    return TypeCreator.REQUIRED.struct(Stream.concat(groupingTypes, measureTypes));
   }
 
   @Override

isthmus/src/test/java/io/substrait/isthmus/TpcdsQueryTest.java

@@ -15,7 +15,7 @@
 public class TpcdsQueryTest extends PlanTestBase {
   private static final Set<Integer> toSubstraitExclusions = Set.of(9, 27, 36, 70, 86);
   private static final Set<Integer> fromSubstraitPojoExclusions = Set.of(1, 30, 81);
-  private static final Set<Integer> fromSubstraitProtoExclusions = Set.of(1, 30, 67, 81);
+  private static final Set<Integer> fromSubstraitProtoExclusions = Set.of(1, 30, 81);
 
   static IntStream testCases() {
     return IntStream.rangeClosed(1, 99).filter(n -> !toSubstraitExclusions.contains(n));