diff --git a/src/sql/rewrite/ob_transform_aggr_subquery.cpp b/src/sql/rewrite/ob_transform_aggr_subquery.cpp
index 044837445c..5d7359a3d6 100644
--- a/src/sql/rewrite/ob_transform_aggr_subquery.cpp
+++ b/src/sql/rewrite/ob_transform_aggr_subquery.cpp
@@ -872,6 +872,7 @@ int ObTransformAggrSubquery::deduce_query_values(ObDMLStmt &stmt,
       // replace_columns_and_aggrs() may change expr result type, e.g.: sum() from ObNumberType
       // to ObNullType. This may cause operand implicit cast be added twice, so we erase it first.
       ObRawExpr *default_expr = NULL;
+      ObRawExpr *case_when_expr = NULL;
       if (OB_FAIL(real_values.push_back(view_columns.at(i)))) {
         LOG_WARN("failed to push back view columns", K(ret));
       } else if (is_null_prop.at(i) || !is_outer_join) {
@@ -890,9 +891,18 @@ int ObTransformAggrSubquery::deduce_query_values(ObDMLStmt &stmt,
                                                                 not_null_expr,
                                                                 view_columns.at(i),
                                                                 default_expr,
-                                                                real_values.at(i),
+                                                                case_when_expr,
                                                                 ctx_))) {
         LOG_WARN("failed to build case when expr", K(ret));
+      } else if (OB_ISNULL(case_when_expr)) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_WARN("case when expr is null", K(ret));
+      } else if (OB_FAIL(ObRawExprUtils::try_add_cast_expr_above(ctx_->expr_factory_,
+                                                                 ctx_->session_info_,
+                                                                 *case_when_expr,
+                                                                 view_columns.at(i)->get_result_type(),
+                                                                 real_values.at(i)))) {
+        LOG_WARN("failed to add cast expr", K(ret));
       }
     }
   }
diff --git a/src/sql/rewrite/ob_transform_groupby_pullup.cpp b/src/sql/rewrite/ob_transform_groupby_pullup.cpp
index 81f3443002..00a6acdbae 100644
--- a/src/sql/rewrite/ob_transform_groupby_pullup.cpp
+++ b/src/sql/rewrite/ob_transform_groupby_pullup.cpp
@@ -923,8 +923,15 @@ int ObTransformGroupByPullup::wrap_case_when(ObSelectStmt &child_stmt,
                                                               case_when_expr,
                                                               ctx_))) {
       LOG_WARN("failed to build case when expr", K(ret));
-    } else {
-      expr = case_when_expr;
+    } else if (OB_ISNULL(case_when_expr)) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("case when expr is null", K(ret));
+    } else if (OB_FAIL(ObRawExprUtils::try_add_cast_expr_above(ctx_->expr_factory_,
+                                                               ctx_->session_info_,
+                                                               *case_when_expr,
+                                                               expr->get_result_type(),
+                                                               expr))) {
+      LOG_WARN("failed to add cast expr", K(ret));
     }
   }
   return ret;
diff --git a/src/sql/rewrite/ob_transform_groupby_pushdown.cpp b/src/sql/rewrite/ob_transform_groupby_pushdown.cpp
index 7c8f4d3a0e..1fcc1accdc 100644
--- a/src/sql/rewrite/ob_transform_groupby_pushdown.cpp
+++ b/src/sql/rewrite/ob_transform_groupby_pushdown.cpp
@@ -158,23 +158,6 @@ int ObTransformGroupByPushdown::adjust_transform_types(uint64_t &transform_types
   return ret;
 }
 
-int ObTransformGroupByPushdown::check_join_condition_contain_lob(ObDMLStmt &stmt, bool &is_valid)
-{
-  int ret = OB_SUCCESS;
-  bool has_lob = false;;
-  ObSEArray<ObRawExpr *, 4> conditions;
-  if (OB_FAIL(append(conditions, stmt.get_condition_exprs()))) {
-    LOG_WARN("extract colum failed", K(ret));
-  } else if (OB_FAIL(ObTransformUtils::get_on_conditions(stmt, conditions))) {
-    LOG_WARN("failed to get all on conditions", K(ret));
-  } else if (OB_FAIL(ObTransformUtils::check_exprs_contain_lob_type(conditions, has_lob))) {
-    LOG_WARN("check lob failed", K(ret));
-  } else {
-    is_valid = !has_lob;
-  }
-  return ret;
-}
-
 int ObTransformGroupByPushdown::check_groupby_push_down_validity(ObSelectStmt *stmt,
                                                                   bool &is_valid)
 {
@@ -222,8 +205,6 @@ int ObTransformGroupByPushdown::check_groupby_push_down_validity(ObSelectStmt *s
     LOG_WARN("failed to check collation validity", K(ret));
   } else if (!is_valid) {
     // do nothing
-  } else if (OB_FAIL(check_join_condition_contain_lob(*stmt, is_valid))) {
-     LOG_WARN("check join condition contain clob failed", K(ret));
   }
   for (int64_t i = 0; OB_SUCC(ret) && is_valid && i < stmt->get_aggr_item_size(); ++i) {
     ObAggFunRawExpr *aggr_expr = NULL;
diff --git a/src/sql/rewrite/ob_transform_groupby_pushdown.h b/src/sql/rewrite/ob_transform_groupby_pushdown.h
index eaef199653..9a4251b345 100644
--- a/src/sql/rewrite/ob_transform_groupby_pushdown.h
+++ b/src/sql/rewrite/ob_transform_groupby_pushdown.h
@@ -200,7 +200,6 @@ private:
                               bool disassemble_join = true);
   int check_hint_valid(ObDMLStmt &stmt, ObIArray<PushDownParam> &params, bool &is_valid);
 
-   int check_join_condition_contain_lob(ObDMLStmt &stmt, bool &is_valid);
 private:
   // help functions
   int64_t get_count_sum_num(const ObIArray<ObRawExpr *> &exprs)
diff --git a/src/sql/rewrite/ob_transform_view_merge.cpp b/src/sql/rewrite/ob_transform_view_merge.cpp
index ee1d7698e4..f51774b62a 100644
--- a/src/sql/rewrite/ob_transform_view_merge.cpp
+++ b/src/sql/rewrite/ob_transform_view_merge.cpp
@@ -1232,8 +1232,15 @@ int ObTransformViewMerge::wrap_case_when(ObSelectStmt &child_stmt,
                                                               case_when_expr,
                                                               ctx_))) {
       LOG_WARN("failed to build case when expr", K(ret));
-    } else {
-      expr = case_when_expr;
+    } else if (OB_ISNULL(case_when_expr)) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("case expr is null", K(ret), K(case_when_expr));
+    } else if (OB_FAIL(ObRawExprUtils::try_add_cast_expr_above(ctx_->expr_factory_,
+                                                               ctx_->session_info_,
+                                                               *case_when_expr,
+                                                               expr->get_result_type(),
+                                                               expr))) {
+      LOG_WARN("failed to add cast expr above", K(ret));
     }
   }
   return ret;
diff --git a/src/sql/rewrite/ob_transform_where_subquery_pullup.cpp b/src/sql/rewrite/ob_transform_where_subquery_pullup.cpp
index 30c9f66ede..e1b1c054a5 100644
--- a/src/sql/rewrite/ob_transform_where_subquery_pullup.cpp
+++ b/src/sql/rewrite/ob_transform_where_subquery_pullup.cpp
@@ -1488,8 +1488,15 @@ int ObWhereSubQueryPullup::wrap_case_when(ObSelectStmt &child_stmt,
                                                               case_when_expr,
                                                               ctx_))) {
       LOG_WARN("failed to build case when expr", K(ret));
-    } else {
-      expr = case_when_expr;
+    } else if (OB_ISNULL(case_when_expr)) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("case when expr is null", K(ret));
+    } else if (OB_FAIL(ObRawExprUtils::try_add_cast_expr_above(ctx_->expr_factory_,
+                                                               ctx_->session_info_,
+                                                               *case_when_expr,
+                                                               expr->get_result_type(),
+                                                               expr))) {
+      LOG_WARN("failed to add cast expr above", K(ret));
     }
   }
   return ret;