OCP 1Z0 053 106

ABKYH

106.You are working as a DBA on the decision support system. There is a business requirement to track
and store all transactions for at least three years for a few tables in the database. Automatic undo
management is enabled in the database. Which configuration should you use to accomplish this task?
A. Enable Flashback Data Archive for the tables.
B. Specify undo retention guarantee for the database.
C. Enable supplemental logging for the database.
D. Query V$UNDOSTAT to determine the amount of undo that will be generated and create an undo
tablespace for that size.
E. Create Flashback Data Archive on the tablespace on which the tables are stored.
Answer: A

flashback table 是通过undo跟踪所有表的数据变化。限于undo的大小，只能闪回短时间内的数据。
　　而Flashback Data Archive可以单独保存指定一个或多个表的的变化信息
　　

http://docs.oracle.com/cd/E11882_01/appdev.112/e41502/adfns_flashback.htm#ADFNS01011
Using Flashback Data Archive (Oracle Total Recall)
A Flashback Data Archive provides the ability to track and store transactional changes to a table over its lifetime. A Flashback Data Archive is usefulfor compliance with record stage policies and audit reports.
A Flashback Data Archive consists of one or more tablespaces or parts thereof. You can have multiple Flashback Data Archives. If you are logged on as SYSDBA, you can specify a default Flashback Data Archive for the system.A Flashback Data Archive is configured with retention time. Data archived in the Flashback Data Archive is retained for the retention time.
By default, flashback archiving is off for any table. You can enable flashback archiving for a table if all of these conditions are true:

• You have the FLASHBACK ARCHIVE object privilege on the Flashback Data Archive to use for that table.
  
• The table is neither nested, clustered, temporary, remote, or external.
  
• The table contains neither LONG nor nested columns.
  
• The table does not use any of these Flashback Data Archive reserved words as column names:
  
  
  
  • STARTSCN
    
  • ENDSCN
    
  • RID
    
  • XID
    
  • OP
    
  • OPERATION
    
  
  

After flashback archiving is enabled for a table, you can disable it only if you either have the FLASHBACK ARCHIVE ADMINISTER system privilege or youare logged on as SYSDBA.
When choosing a Flashback Data Archive for a specific table, consider the data retention requirements for the table and the retention times of the Flashback Data Archives on which you have the FLASHBACK ARCHIVE objectprivilege.

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