[单选]

You want to configure the Flashback Database feature and retain flashback logs for three days. 
Presently the database is open and configured in ARCHIVELOG mode. The following steps must be performed in the correct sequence to do this：  
1. Set the retention target： 
SQL> ALTER SYSTEM SET DB_FLASHBACK_RETENTION_TARGET=4320； 
2. Enable Flashback Database： 
SQL> ALTER DATABASE FLASHBACK ON； 
3. Mount the database： 
SQL> STARTUP MOUNT EXCLUSIVE 
4. Shutdown the instance： SQL> SHUTDOWN IMMEDIATE 
5. Open the database： 
SQL> ALTER DATABASE OPEN；  
Choose the correct sequence.（）

Which of the following procedures best explains how to enable the NIS name resolution to take precedence over DNS on a system-wide basis?（）  Add the following line to /etc/netsvc.conf: hosts = nis,bind,local 。  edit /etc/netsvc.conf to add the following: process /full/path/of/process \{ hosts = local,nis,dns} 。  In an NIS and DNS environment, NIS takes precedence over DNS in this environment resulting in no change 。  Change the NSORDER environment variable&e。 层次分析是分析多因素对竞争力影响的常用工具时，以下对层次分析的描述不正确的是（）。 层次分析特点是可以细致周全的比对各因素的影响。 层次分析是通过因素对比和权重，评价不同对象的竞争力差异。 层次分析能为决策都提出最优的新方案。 层次分析相对繁琐，定性数据较多。 Which of the following statements is TRUE concerning the po column of the vmstat command？（）  The sys is high when po is high.。  The po represents the number of page steals.。  The low values usually indicate insufficient paging space.。  The low values usually indicate sufficient memory for the load.。 How would the system administrator find information regarding smit menu definitions？（） Use ODM commands。 Use LVM commands。 In the /etc/environment file。 In the /usr/lib/smit/menu.cfg file。 You performed the RMAN database backup having a backupset key number 231 with the KEEP FOREVER option. After some days, you want to change the status of the database backup and you issued the following command: RMAN>CHANGE BACKUPSET 231 NOKEEP; What is the implication of this command?（） The backup is deleted.。 The backup is marked unavailable.。 The backup overrides the backup retention policy.。 the backup becomes eligible for deletion according to the existing retention policy。

You want to configure the Flashback Database feature and retain flashback logs for three days. 
Presently the database is open and configured in ARCHIVELOG mode. The following steps must be performed in the correct sequence to do this：  
1. Set the retention target： 
SQL> ALTER SYSTEM SET DB_FLASHBACK_RETENTION_TARGET=4320； 
2. Enable Flashback Database： 
SQL> ALTER DATABASE FLASHBACK ON； 
3. Mount the database： 
SQL> STARTUP MOUNT EXCLUSIVE 
4. Shutdown the instance： SQL> SHUTDOWN IMMEDIATE 
5. Open the database： 
SQL> ALTER DATABASE OPEN；  
Choose the correct sequence.（）