内径百分表可以用来测量孔径和孔的（）误差。
You are maintaining the SALES database for an organization. You have enabled the Flashback Database feature and want to estimate the flashback space required for future operations. Which view would you query to estimate the flashback space required？（） V$DATABASE。 V$FLASHBACK_DATABASE_STAT。 V$FLASHBACK_DATABASE_LOG。 V$RECOVERY_FILE_DEST。
教师权威
Your database is open and the LISTENER listener is running. The new DBA of the system stops thelistener by using the command： LSNRCTL> STOP What happens to the sessions that are presently connected to the database instance（） The sessions are able to perform only queries.。 The sessions are not affected and continue to function normally.。 The sessions are terminated and the active transactions are rolled back.。 The sessions are not allowed to perform any operations till the listener is started.。
若被测机械的转向改变，则交流测速发电机输出电压的（）。 频率改变。 大小改变。 相位改变90°。 相位改变180°。
You are working as a DBA in an organization. The flash recovery area files are created in ’+disk1’. You want to create new flash recovery area files in the ’+disk2’ location. The new location of the flash recovery area files should be written in the control file and the spfile.Which command will you issue to change the location of the flash recovery area files？（）
