diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
index 7fc87c22089c8..70fb9b08d62bc 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
@@ -60,12 +60,20 @@ case class Aggregate(
 
   def output = aggregateExpressions.map(_.toAttribute)
 
+  /**
+   * An aggregate that needs to be computed for each row in a group.
+   *
+   * @param unbound Unbound version of this aggregate, used for result substitution.
+   * @param aggregate A bound copy of this aggregate used to create a new aggregation buffer.
+   * @param resultAttribute An attribute used to refer to the result of this aggregate in the final
+   *                        output.
+   */
   case class ComputedAggregate(
-      unbound: AggregateExpression,        // Unbound aggregate used for result substitution
-      aggregate: AggregateExpression,      // A bound copy of this aggregate used to create a buffer
-      resultAttribute: AttributeReference) // An attribute used to refer to the result of this agg
+      unbound: AggregateExpression,
+      aggregate: AggregateExpression,
+      resultAttribute: AttributeReference)
 
-  // A list of aggregates that need to be computed for each group.
+  /** A list of aggregates that need to be computed for each group. */
   @transient
   lazy val computedAggregates = aggregateExpressions.flatMap { agg =>
     agg.collect {
@@ -77,11 +85,11 @@ case class Aggregate(
     }
   }.toArray
 
-  // The schema of the result of all aggregate evaluations
+  /** The schema of the result of all aggregate evaluations */
   @transient
   lazy val computedSchema = computedAggregates.map(_.resultAttribute)
 
-  // Creates a new aggregate buffer for a group.
+  /** Creates a new aggregate buffer for a group. */
   def newAggregateBuffer(): Array[AggregateFunction] = {
     val buffer = new Array[AggregateFunction](computedAggregates.length)
     var i = 0
@@ -92,21 +100,25 @@ case class Aggregate(
     buffer
   }
 
-  // Named attributes used to substitute grouping attributes into the final result.
+  /** Named attributes used to substitute grouping attributes into the final result. */
   @transient
   lazy val namedGroups = groupingExpressions.map {
     case ne: NamedExpression => ne -> ne.toAttribute
     case e => e -> Alias(e, s"groupingExpr:$e")().toAttribute
   }
 
-  // A map of substitutions that are used to insert the aggregate expressions and grouping
-  // expression into the final result expression.
+  /**
+   * A map of substitutions that are used to insert the aggregate expressions and grouping
+   * expression into the final result expression.
+   */
   @transient
   lazy val resultMap =
     (computedAggregates.map { agg => agg.unbound -> agg.resultAttribute} ++ namedGroups).toMap
 
-  // Substituted version of aggregateExpressions expressions which are used to compute final
-  // output rows given a group and the result of all aggregate computations.
+  /**
+   * Substituted version of aggregateExpressions expressions which are used to compute final
+   * output rows given a group and the result of all aggregate computations.
+   */
   @transient
   lazy val resultExpressions = aggregateExpressions.map { agg =>
     agg.transform {