diff --git a/velox/functions/prestosql/aggregates/CMakeLists.txt b/velox/functions/prestosql/aggregates/CMakeLists.txt
index 4e467bab1f66..986de438474e 100644
--- a/velox/functions/prestosql/aggregates/CMakeLists.txt
+++ b/velox/functions/prestosql/aggregates/CMakeLists.txt
@@ -36,7 +36,8 @@ velox_add_library(
   MapUnionSumAggregate.cpp
   MaxSizeForStatsAggregate.cpp
   MinMaxAggregates.cpp
-  MinMaxByAggregates.cpp
+  MaxByAggregate.cpp
+  MinByAggregate.cpp
   MultiMapAggAggregate.cpp
   PrestoHasher.cpp
   ReduceAgg.cpp
diff --git a/velox/functions/prestosql/aggregates/MaxByAggregate.cpp b/velox/functions/prestosql/aggregates/MaxByAggregate.cpp
new file mode 100644
index 000000000000..60cc72f008b4
--- /dev/null
+++ b/velox/functions/prestosql/aggregates/MaxByAggregate.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "velox/functions/prestosql/aggregates/AggregateNames.h"
+#include "velox/functions/prestosql/aggregates/MinMaxByAggregateBase.h"
+
+namespace facebook::velox::aggregate::prestosql {
+
+template <typename V, typename C>
+class MaxByNAggregate : public MinMaxByNAggregate<V, C, Greater<V, C>> {
+ public:
+  explicit MaxByNAggregate(TypePtr resultType)
+      : MinMaxByNAggregate<V, C, Greater<V, C>>(resultType) {}
+};
+
+template <typename C>
+class MaxByNAggregate<ComplexType, C>
+    : public MinMaxByNAggregate<
+          ComplexType,
+          C,
+          Greater<HashStringAllocator::Position, C>> {
+ public:
+  explicit MaxByNAggregate(TypePtr resultType)
+      : MinMaxByNAggregate<
+            ComplexType,
+            C,
+            Greater<HashStringAllocator::Position, C>>(resultType) {}
+};
+
+void registerMaxByAggregates(
+    const std::string& prefix,
+    bool withCompanionFunctions,
+    bool overwrite) {
+  registerMinMaxBy<
+      functions::aggregate::MinMaxByAggregateBase,
+      true,
+      MaxByNAggregate>(prefix + kMaxBy, withCompanionFunctions, overwrite);
+}
+
+} // namespace facebook::velox::aggregate::prestosql
diff --git a/velox/functions/prestosql/aggregates/MinByAggregate.cpp b/velox/functions/prestosql/aggregates/MinByAggregate.cpp
new file mode 100644
index 000000000000..6d47f73867dd
--- /dev/null
+++ b/velox/functions/prestosql/aggregates/MinByAggregate.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "velox/functions/prestosql/aggregates/AggregateNames.h"
+#include "velox/functions/prestosql/aggregates/MinMaxByAggregateBase.h"
+
+namespace facebook::velox::aggregate::prestosql {
+
+template <typename V, typename C>
+class MinByNAggregate : public MinMaxByNAggregate<V, C, Less<V, C>> {
+ public:
+  explicit MinByNAggregate(TypePtr resultType)
+      : MinMaxByNAggregate<V, C, Less<V, C>>(resultType) {}
+};
+
+template <typename C>
+class MinByNAggregate<ComplexType, C>
+    : public MinMaxByNAggregate<
+          ComplexType,
+          C,
+          Less<HashStringAllocator::Position, C>> {
+ public:
+  explicit MinByNAggregate(TypePtr resultType)
+      : MinMaxByNAggregate<
+            ComplexType,
+            C,
+            Less<HashStringAllocator::Position, C>>(resultType) {}
+};
+
+void registerMinByAggregates(
+    const std::string& prefix,
+    bool withCompanionFunctions,
+    bool overwrite) {
+  registerMinMaxBy<
+      functions::aggregate::MinMaxByAggregateBase,
+      false,
+      MinByNAggregate>(prefix + kMinBy, withCompanionFunctions, overwrite);
+}
+
+} // namespace facebook::velox::aggregate::prestosql
diff --git a/velox/functions/prestosql/aggregates/MinMaxByAggregates.cpp b/velox/functions/prestosql/aggregates/MinMaxByAggregateBase.h
similarity index 95%
rename from velox/functions/prestosql/aggregates/MinMaxByAggregates.cpp
rename to velox/functions/prestosql/aggregates/MinMaxByAggregateBase.h
index 71f020ca398c..5f6c57690594 100644
--- a/velox/functions/prestosql/aggregates/MinMaxByAggregates.cpp
+++ b/velox/functions/prestosql/aggregates/MinMaxByAggregateBase.h
@@ -21,12 +21,8 @@
 #include "velox/functions/prestosql/aggregates/AggregateNames.h"
 #include "velox/type/FloatingPointUtil.h"
 
-using namespace facebook::velox::functions::aggregate;
-
 namespace facebook::velox::aggregate::prestosql {
 
-namespace {
-
 /// Returns true if the value in 'index' row of 'newComparisons' is strictly
 /// greater than or less than the value in the 'accumulator'.
 template <bool greaterThan, typename T, typename TAccumulator>
@@ -36,7 +32,7 @@ struct Comparator {
       const DecodedVector& newComparisons,
       vector_size_t index,
       bool isFirstValue) {
-    if constexpr (isNumeric<T>()) {
+    if constexpr (functions::aggregate::isNumeric<T>()) {
       if (isFirstValue) {
         return true;
       }
@@ -1017,48 +1013,6 @@ class MinMaxByNAggregate : public exec::Aggregate {
   DecodedVector decodedIntermediates_;
 };
 
-template <typename V, typename C>
-class MinByNAggregate : public MinMaxByNAggregate<V, C, Less<V, C>> {
- public:
-  explicit MinByNAggregate(TypePtr resultType)
-      : MinMaxByNAggregate<V, C, Less<V, C>>(resultType) {}
-};
-
-template <typename C>
-class MinByNAggregate<ComplexType, C>
-    : public MinMaxByNAggregate<
-          ComplexType,
-          C,
-          Less<HashStringAllocator::Position, C>> {
- public:
-  explicit MinByNAggregate(TypePtr resultType)
-      : MinMaxByNAggregate<
-            ComplexType,
-            C,
-            Less<HashStringAllocator::Position, C>>(resultType) {}
-};
-
-template <typename V, typename C>
-class MaxByNAggregate : public MinMaxByNAggregate<V, C, Greater<V, C>> {
- public:
-  explicit MaxByNAggregate(TypePtr resultType)
-      : MinMaxByNAggregate<V, C, Greater<V, C>>(resultType) {}
-};
-
-template <typename C>
-class MaxByNAggregate<ComplexType, C>
-    : public MinMaxByNAggregate<
-          ComplexType,
-          C,
-          Greater<HashStringAllocator::Position, C>> {
- public:
-  explicit MaxByNAggregate(TypePtr resultType)
-      : MinMaxByNAggregate<
-            ComplexType,
-            C,
-            Greater<HashStringAllocator::Position, C>>(resultType) {}
-};
-
 template <template <typename U, typename V> class NAggregate, typename W>
 std::unique_ptr<exec::Aggregate> createNArg(
     TypePtr resultType,
@@ -1142,7 +1096,7 @@ std::unique_ptr<exec::Aggregate> createNArg(
   }
 }
 
-std::string toString(const std::vector<TypePtr>& types) {
+inline std::string toString(const std::vector<TypePtr>& types) {
   std::ostringstream out;
   for (auto i = 0; i < types.size(); ++i) {
     if (i > 0) {
@@ -1239,7 +1193,7 @@ exec::AggregateRegistrationResult registerMinMaxBy(
           return createNArg<NAggregate>(
               resultType, argTypes[0], argTypes[1], errorMessage);
         } else {
-          return create<Aggregate, Comparator, isMaxFunc>(
+          return functions::aggregate::create<Aggregate, Comparator, isMaxFunc>(
               resultType, argTypes[0], argTypes[1], errorMessage, true);
         }
       },
@@ -1247,16 +1201,4 @@ exec::AggregateRegistrationResult registerMinMaxBy(
       overwrite);
 }
 
-} // namespace
-
-void registerMinMaxByAggregates(
-    const std::string& prefix,
-    bool withCompanionFunctions,
-    bool overwrite) {
-  registerMinMaxBy<MinMaxByAggregateBase, true, MaxByNAggregate>(
-      prefix + kMaxBy, withCompanionFunctions, overwrite);
-  registerMinMaxBy<MinMaxByAggregateBase, false, MinByNAggregate>(
-      prefix + kMinBy, withCompanionFunctions, overwrite);
-}
-
 } // namespace facebook::velox::aggregate::prestosql
diff --git a/velox/functions/prestosql/aggregates/RegisterAggregateFunctions.cpp b/velox/functions/prestosql/aggregates/RegisterAggregateFunctions.cpp
index 1aafe15371a8..53bf0ce22ba9 100644
--- a/velox/functions/prestosql/aggregates/RegisterAggregateFunctions.cpp
+++ b/velox/functions/prestosql/aggregates/RegisterAggregateFunctions.cpp
@@ -129,7 +129,11 @@ extern void registerMinMaxAggregates(
     const std::string& prefix,
     bool withCompanionFunctions,
     bool overwrite);
-extern void registerMinMaxByAggregates(
+extern void registerMaxByAggregates(
+    const std::string& prefix,
+    bool withCompanionFunctions,
+    bool overwrite);
+extern void registerMinByAggregates(
     const std::string& prefix,
     bool withCompanionFunctions,
     bool overwrite);
@@ -176,7 +180,8 @@ void registerAllAggregateFunctions(
   registerSumDataSizeForStatsAggregate(
       prefix, withCompanionFunctions, overwrite);
   registerMinMaxAggregates(prefix, withCompanionFunctions, overwrite);
-  registerMinMaxByAggregates(prefix, withCompanionFunctions, overwrite);
+  registerMaxByAggregates(prefix, withCompanionFunctions, overwrite);
+  registerMinByAggregates(prefix, withCompanionFunctions, overwrite);
   registerReduceAgg(prefix, withCompanionFunctions, overwrite);
   registerSetAggAggregate(prefix, withCompanionFunctions, overwrite);
   registerSetUnionAggregate(prefix, withCompanionFunctions, overwrite);