[单选]

Consider the following scenario： You have a directory， data， under the disk group tdgroupA. You want to create an alias for one of the data files and you execute the following command： ALTER DISKGROUP tdgroupA 
ADD ALIAS ’+tdgroupA/data/datafile.dbf’ 
FOR ’+tdgroupA.231.45678’； 
Which task would be accomplished by the command？（）

接入功率方向继电器的电流和电压为IA，Ubc，Ib²UcA，Ic²UAb时称为（）。 90°接线。 60接线°。 30°接线。 小学德育的基本内容是（） 革命理想和传统教育。 民主和法制观念的启蒙教。 辩证唯物主义观念的启蒙教育。 道德教育。 Given: What is the result?（） test。 null。 An exception is thrown at runtime.。 Compilation fails because of an error in line 1.。 Compilation fails because of an error in line 4.。 Compilation fails because of an error in line 5.。 气质类型（） 有好好坏。 都是好的。 都是坏的。 无好坏之分。 Your database is running in ARCHIVELOG mode. You are performing a user-managed backup of the DATA1 tablespace. You place the DATA1 tablespace in backup mode by issuing the following statement: ALTER TABLESPACE data1 BEGIN BACKUP; While you are performing the backup, an error occurs that causes the instance to terminate abnormally. Which statement about the DATA1 tablespace is true?（） The DATA1 tablespace is automatically taken out of backup mode when the instance aborts.。 If you restart the database, the DATA1 tablespace will be automatically taken out of backup mode when the database is opened.。 If you restart the database, the DATA1 tablespace will be automatically taken out of backup mode when the database is mounted.。 If you restart the database, the database will not be opened.。

Consider the following scenario： You have a directory， data， under the disk group tdgroupA. You want to create an alias for one of the data files and you execute the following command： ALTER DISKGROUP tdgroupA 
ADD ALIAS ’+tdgroupA/data/datafile.dbf’ 
FOR ’+tdgroupA.231.45678’； 
Which task would be accomplished by the command？（）