[单选]

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？（）  

Examine the following command that is used to duplicate a database on the same host: RMAN> RUN { ALLOCATE AUXILIARY CHANNEL, aux 1 DEVICE TYPE DISK; DUPLICATE TARGET DATABASE TO auxdb SKIP READONLY; \ } Which two statements describe the effect after the database is duplicated successfully? （）(Choose two) The data files of the read-only tablespaces in the target database are not duplicated。 The read-only tablespaces in the target database are still defined in new the database。 The read-only tablespaces in the target database are changed to online after duplication。 The data files of the read-only tablespaces in the target database get duplicated。 The read-only tablespaces in the target database are not defined in the new database。 狭义上的纳税主体包括（）。 法律、行政法规规定负有纳税义务的单位。 法律、行政法规规定负有纳税义务的个人。 法律、行政法规规定负有代扣代缴、代收代缴税款义务的单位。 法律、行政法规规定负有代扣代缴、代收代缴税款义务的个人。 You issued the following statement：  SQL> ALTER DATABASE BACKUP CONTROLFILE TO TRACE；  What will be the result of issuing the statement？（）    The control file will be multiplexed.。  The control file will be recreated.。 The script containing the CREATE CONTROLFILE statement will be created.。  The binary backup of the control file will be created.。 在验收工作中进一步落实水利工程建设项目法人责任制，强调（）以及其他参建单位应当提交真实、完整的验收资料，并对提交的资料负责。 监理人。 投标人。 项目法人。 以上都不对。 You need to perform a block media recovery on the tools01.dbf data file in the SALES database by using Recovery Manager (RMAN). Which two are the prerequisites to perform this operation? （）(Choose two) You must configure block change tracking file。 You must have first level 1 backups for RMAN to restore blocks。 You must ensure that the SALES database is mounted or open。 You must have full or level 0 backups for RMAN to restore blocks。 You must take the tools01.dbf data file offline before you start a block media recovery。

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？（）