[SCN REFACTOR] replace flash back snapshot and remove read snapshot session

src/rootserver/ddl_task/ob_column_redefinition_task.h

@@ -44,6 +44,7 @@ public:
   virtual int update_complete_sstable_job_status(
     const common::ObTabletID &tablet_id,
     const int64_t snapshot_version,
+    const int64_t execution_id,
     const int ret_code) override;
 private:
   int wait_data_complement(const share::ObDDLTaskStatus next_task_status);