dblink_write implement [FEAT MERGE]

Co-authored-by: zzg19950727 <1071026277@qq.com>
Co-authored-by: xianyu-w <707512433@qq.com>

src/sql/optimizer/ob_update_log_plan.h

@@ -28,13 +28,14 @@ namespace sql
     {}
     virtual ~ObUpdateLogPlan() {}
 
-    virtual int generate_raw_plan() override;
-
     const ObUpdateStmt *get_stmt() const override
     { return reinterpret_cast<const ObUpdateStmt*>(stmt_); }
 
     int perform_vector_assign_expr_replacement(ObUpdateStmt *stmt);
 
+  protected:
+    virtual int generate_normal_raw_plan() override;
+
   private:
     int candi_allocate_update();
     int candi_allocate_pdml_update();