1Z0-042
多选题Which two statements about Flashback Query are true？（）AIt is generated by using the redo log files.BIt helps in row-level recovery from user errors.CIt can be performed to recover ALTER TABLE statementsDIt fails when undo data pertaining to the transac
题目
It is generated by using the redo log files.
It helps in row-level recovery from user errors.
It can be performed to recover ALTER TABLE statements
It fails when undo data pertaining to the transaction is overwritten.
The database has to be opened with the resetlogs option after performing Flashback Query.
参考答案和解析
相似问题和答案
第1题：
A. All the related indexes and views are automatically dropped
B. The flashback drop feature can recover only the table structure
C. Only the related indexes are dropped whereas views are invalidated
D. The flashback drop feature can recover both the table structure and its data
第2题：
You are working in an online transaction processing （OLTP） environment. You realize that the salary for an employee， John， has been accidentally modified in the EMPLOYEES table. Two days ago， the data was in the correct state. Flashback logs generated during last two days are available in the flash recovery area. Which option would you choose to bring the data to the correct state while ensuring that no other data in the same table is affected？（）
- A、perform point-in-time recovery
- B、perform a Flashback Table operation to restore the table to the state it was in two days ago
- C、perform a Flashback Database operation to restore the database to the state it was in two days ago
- D、perform Flashback Versions Query and Flashback Transaction Query to determine all the necessary undo SQL statements， and then use them for recovery
正确答案:D
第3题：
A. All the related indexes and views are automatically dropped
B. The flashback drop feature can recover only the table structure
C. Only the related indexes are dropped whereas views are invalidated
D. The flashback drop feature can recover both the table structure and its data
第4题：
Which two statements about Flashback Query are true？（）
- A、It is generated by using the redo log files.
- B、It helps in row-level recovery from user errors.
- C、It can be performed to recover ALTER TABLE statements
- D、It fails when undo data pertaining to the transaction is overwritten.
- E、The database has to be opened with the resetlogs option after performing Flashback Query.
正确答案:B,D
第5题：
The RECYCLEBIN parameter is set to ON for your database. You drop a table，PRODUCTS，from the SCOTT schema. Which two statements are true regarding the outcome of this action？（）
- A、 All the related indexes and views are automatically dropped
- B、 The flashback drop feature can recover only the table structure
- C、 Only the related indexes are dropped whereas views are invalidated
- D、 The flashback drop feature can recover both the table structure and its data
正确答案:C,D
第6题：
The RECYCLEBIN parameter is set to ON for your database. You drop a table, PRODUCTS, from the SCOTT schema. Which two statements are true regarding the outcome of this action? （）(Choose two)
- A、All the related indexes and views are automatically dropped
- B、The flashback drop feature can recover only the table structure
- C、Only the related indexes are dropped whereas views are invalidated
- D、The flashback drop feature can recover both the table structure and its data
正确答案:C,D
第7题：
These are the details about V$FLASHBACK_DATABASE_STAT： SQL> DESC V$FLASHBACK_DATABASE_STAT Name Null？ Type ------------- -------- -------------- BEGIN_TIME DATE END_TIME DATE FLASHBACK_DATA NUMBER DB_DATA NUMBER REDO_DATA NUMBER ESTIMATED_FLASHBACK_SIZE NUMBER Which two statements regarding the V$FLASHBACK_DATABASE_STAT view are true？ （）
- A、BEGIN_TIME is the time at which Flashback logging is enabled.
- B、END_TIME is the time at which the query is executed on the view.
- C、REDO_DATA is the number of bytes of redo data written during the interval.
- D、This view contains information about flashback data pertaining to the last 24 hours.
- E、FLASHBACK_DATA is the amount of flashback data generated since the database was opened.
正确答案:C,D
第8题：
A. Flashback Table can be performed on system tables.
B. Flashback Table operation does not shrink the segments.
C. Flashback Table uses log mining to extract SQL_REDO and SQL_UNDO statements.
D. Flashback Table operation acquires exclusive data manipulation language (DML) locks.
第9题：
These are the details about V$FLASHBACK_DATABASE_STAT： SQL> DESC v$FLASHBACK_DATABASE_STAT Name Null？ Type ------------- -------- -------------- BEGIN_TIME DATE END_TIME DATE FLASHBACK_DATA NUMBER DB_DATA NUMBER REDO_DATA NUMBER ESTIMATED_FLASHBACK_SIZE NUMBER Which two statements regarding the V$FLASHBACK_DATABASE_STATview aretrue？ （）
- A、 BEGIN_TIME is the time at which Flashback logging is enabled.
- B、 END_TIME is the time at which the query is executed on the view.
- C、 REDO_DATA is the number of bytes of redo data written during the interval.
- D、 This view contains information about flashback data pertaining to the last 24 hours.
- E、 FLASHBACK_DATA is the amount of flashback data generated since the database was opened.
正确答案:C,D
第10题：
You lost the PRODSTD tablespace， which was read/write. The tablespace was read-only when the last backup was performed. How would you recover the tablespace？（）
- A、 restore the tablespace from the backup； there is no need to apply the redo information
- B、 restore the full database to recover the data up to the point when you performed the backup
- C、 restore the tablespace from the backup and then perform a recovery using the backup control file
- D、 restore the tablespace from the backup and then recover the tablespace； all the redo information from the point when the tablespace was made read/write is applied
正确答案:D