diff --git a/src/sql/optimizer/ob_opt_est_sel.cpp b/src/sql/optimizer/ob_opt_est_sel.cpp
index 38152dc90be2fc0f174ad88bff54b66a71ddae4f..84cd36f4f74fcecf2008b266b0c97a21450f7258 100644
--- a/src/sql/optimizer/ob_opt_est_sel.cpp
+++ b/src/sql/optimizer/ob_opt_est_sel.cpp
@@ -34,9 +34,11 @@ using namespace oceanbase::common;
 using namespace oceanbase::share::schema;
 namespace oceanbase {
 namespace sql {
-double ObOptEstSel::DEFAULT_COLUMN_DISTINCT_RATIO = EST_DEF_COL_NUM_DISTINCT * 1.0 / OB_EST_DEFAULT_ROW_COUNT;
+
 constexpr double EPSILON = 0.000000001;
 
+double ObOptEstSel::DEFAULT_COLUMN_DISTINCT_RATIO = EST_DEF_COL_NUM_DISTINCT * 1.0 / OB_EST_DEFAULT_ROW_COUNT;
+
 int ObOptEstSel::calculate_selectivity(const ObEstSelInfo& est_sel_info, const ObIArray<ObRawExpr*>& quals,
     double& selectivity, ObIArray<ObExprSelPair>* all_predicate_sel, ObJoinType join_type, const ObRelIds* left_rel_ids,
     const ObRelIds* right_rel_ids, const double left_row_count, const double right_row_count)