In sna, a request unit sent only in reaction to a received request unit; for example, quiesce complete is the reply sent after receipt of quiesce at end of chain 在系统网络体系结构(sna)中，仅对接受的请求单元进行反馈时发送的一种请求单元。例如，在接受了“链结束停顿”后发送“停顿完成”应答。
Recover history file contains info such as backup and restore of database or tables paces, roll forward recovery from database or table space, altering and quiescing a table space, reorg and runstats, dropping a table etc 恢复历史文件包含像下面的一些信息：数据库或表空间的备份和恢复、从数据库或表空间进行前滚恢复、修改和停止表空间、reorg和runstats、删除表等
