diff --git a/extensions-core/histogram/src/main/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramAggregator.java b/extensions-core/histogram/src/main/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramAggregator.java
index e35cba0a1cf6..ba93ab479af7 100644
--- a/extensions-core/histogram/src/main/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramAggregator.java
+++ b/extensions-core/histogram/src/main/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramAggregator.java
@@ -52,9 +52,6 @@ public ApproximateHistogramAggregator(
   @Override
   public void aggregate()
   {
-    // In case of ExpressionColumnValueSelector isNull will compute the expression and then give the result,
-    // the check for is NullHandling.replaceWithDefault is there to not have any performance impact of calling
-    // isNull for default case.
     if (!selector.isNull()) {
       histogram.offer(selector.getFloat());
     }
diff --git a/extensions-core/multi-stage-query/src/test/java/org/apache/druid/msq/exec/MSQInsertTest.java b/extensions-core/multi-stage-query/src/test/java/org/apache/druid/msq/exec/MSQInsertTest.java
index a07d57f31687..ad020d4548fd 100644
--- a/extensions-core/multi-stage-query/src/test/java/org/apache/druid/msq/exec/MSQInsertTest.java
+++ b/extensions-core/multi-stage-query/src/test/java/org/apache/druid/msq/exec/MSQInsertTest.java
@@ -1763,7 +1763,7 @@ public void testEmptyInsertLimitQuery(String contextName, Map<String, Object> co
 
   private List<Object[]> expectedFooRows()
   {
-    return ImmutableList.of(
+    return Arrays.asList(
         new Object[]{946684800000L, "", 1L},
         new Object[]{946771200000L, "10.1", 1L},
         new Object[]{946857600000L, "2", 1L},
diff --git a/processing/src/main/java/org/apache/druid/frame/field/NumericArrayFieldWriter.java b/processing/src/main/java/org/apache/druid/frame/field/NumericArrayFieldWriter.java
index fd86687e5a49..760374129b38 100644
--- a/processing/src/main/java/org/apache/druid/frame/field/NumericArrayFieldWriter.java
+++ b/processing/src/main/java/org/apache/druid/frame/field/NumericArrayFieldWriter.java
@@ -171,12 +171,6 @@ public void inspectRuntimeShape(RuntimeShapeInspector inspector)
         @Override
         public boolean isNull()
         {
-          // Arrays preserve the individual element's nullity when they are written and read.
-          // Therefore, when working with SQL incompatible mode, [7, null] won't change to [7, 0] when written to and
-          // read from the underlying serialization (as compared with the primitives). Therefore,
-          // even when NullHandling.replaceWithDefault() is true we need to write null as is, and not convert it to their
-          // default value when writing the array. Therefore, the check is `getObject() == null` ignoring the value of
-          // `NullHandling.replaceWithDefaul()`.
           return getObject() == null;
         }
 
diff --git a/processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java b/processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java
index 74846b7b2427..0f64988ddf2e 100644
--- a/processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java
+++ b/processing/src/main/java/org/apache/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java
@@ -644,10 +644,7 @@ public static CloseableGrouperIterator<RowBasedKey, ResultRow> makeGrouperIterat
           for (int i = resultRowDimensionStart; i < entry.getKey().getKey().length; i++) {
             if (dimsToInclude == null || dimsToIncludeBitSet.get(i - resultRowDimensionStart)) {
               final Object dimVal = entry.getKey().getKey()[i];
-              resultRow.set(
-                  i,
-                  dimVal instanceof String ? dimVal : dimVal
-              );
+              resultRow.set(i, dimVal);
             }
           }