Created by Jerry Wang, last modified on Oct 06, 2014
variant 1: 異步update
variant 2： 同步update
variant 3
根據ABAP help 對關鍵字SET UPDATE TASK LOCAL的說明(The local update function performs a synchronous update after the COMMIT WORK statement, independently of the addition AND WAIT), variant 3還是屬于同步update:( 總的gross time仍然為3秒)