diff --git a/src/sql/resolver/dml/ob_dml_stmt.cpp b/src/sql/resolver/dml/ob_dml_stmt.cpp
index a73a49f8da..cb7d667ce8 100644
--- a/src/sql/resolver/dml/ob_dml_stmt.cpp
+++ b/src/sql/resolver/dml/ob_dml_stmt.cpp
@@ -1737,7 +1737,9 @@ int ObDMLStmt::formalize_stmt_expr_reference()
       } else { /*do nothing*/ }
     }
     if (OB_SUCC(ret)) {
-      if (OB_FAIL(remove_useless_sharable_expr())) {
+      if (is_select_stmt() && OB_FAIL(static_cast<ObSelectStmt*>(this)->maintain_scala_group_by_ref())) {
+        LOG_WARN("failed to meantain scala group by", K(ret));
+      } else if (OB_FAIL(remove_useless_sharable_expr())) {
         LOG_WARN("failed to remove useless sharable expr", K(ret));
       } else if (OB_FAIL(check_pseudo_column_valid())) {
         LOG_WARN("failed to check pseudo column", K(ret));
diff --git a/src/sql/resolver/dml/ob_select_stmt.cpp b/src/sql/resolver/dml/ob_select_stmt.cpp
index e999578597..573839f26c 100644
--- a/src/sql/resolver/dml/ob_select_stmt.cpp
+++ b/src/sql/resolver/dml/ob_select_stmt.cpp
@@ -1305,3 +1305,28 @@ ObRawExpr* ObSelectStmt::get_pure_set_expr(ObRawExpr *expr)
   }
   return expr;
 }
+
+// add ref count to the last aggr item to maintain the scala group by
+int ObSelectStmt::maintain_scala_group_by_ref()
+{
+  int ret = OB_SUCCESS;
+  bool has_ref = false;
+  if (is_scala_group_by()) {
+    for (int64_t i = 0; OB_SUCC(ret) && i < agg_items_.count(); ++i) {
+      ObAggFunRawExpr *agg_expr = agg_items_.at(i);
+      if (OB_ISNULL(agg_expr)) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_WARN("agg expr is NULL", K(ret));
+      } else if (agg_expr->is_explicited_reference()) {
+        has_ref = true;
+        break;
+      }
+    }
+    if (OB_FAIL(ret) || has_ref) {
+      // do nothing
+    } else if (OB_FAIL(set_sharable_expr_reference(*agg_items_.at(0), ExplicitedRefType::REF_BY_NORMAL))) {
+      LOG_WARN("fail to set expr reference", K(ret));
+    }
+  }
+  return ret;
+}
\ No newline at end of file
diff --git a/src/sql/resolver/dml/ob_select_stmt.h b/src/sql/resolver/dml/ob_select_stmt.h
index dc26c7d7c4..e3f498d85f 100644
--- a/src/sql/resolver/dml/ob_select_stmt.h
+++ b/src/sql/resolver/dml/ob_select_stmt.h
@@ -438,6 +438,7 @@ public:
   bool has_hidden_rowid() const;
   virtual int clear_sharable_expr_reference() override;
   virtual int remove_useless_sharable_expr() override;
+  int maintain_scala_group_by_ref();
 
   const common::ObIArray<OrderItem>& get_search_by_items() const { return search_by_items_; }
   const common::ObIArray<ColumnItem>& get_cycle_items() const { return cycle_by_items_; }
diff --git a/src/sql/rewrite/ob_transform_count_to_exists.cpp b/src/sql/rewrite/ob_transform_count_to_exists.cpp
index 34447dd3b6..7a1218957c 100644
--- a/src/sql/rewrite/ob_transform_count_to_exists.cpp
+++ b/src/sql/rewrite/ob_transform_count_to_exists.cpp
@@ -434,6 +434,7 @@ int ObTransformCountToExists::do_transform(ObDMLStmt *stmt,
         }
         if (OB_FAIL(ret)) {
         } else if (OB_FALSE_IT(subquery->get_select_items().reuse())) {
+        } else if (OB_FALSE_IT(subquery->get_aggr_items().reuse())) {
         } else if (OB_FAIL(ObTransformUtils::create_dummy_select_item(*subquery, ctx_))) {
           LOG_WARN("failed to create dummy select item", K(ret));
         } else if (OB_FAIL(ObOptimizerUtil::remove_item(stmt->get_condition_exprs(),