多选题The EMP table has some discrepancy in data entry with a particular employee ID. You execute the query as shown in the Exhibit to retrieve all versions of the row that exist between two SCNs. View the Exhibit. Which two statements about the results of

第1题：

You are performing flashback of the EMPLOYEE table in SCOTT’s schema because some incorrect data was inserted into the table and committed by mistake. Which two clauses will you use in the FLASHBACK TABLE statement for using the Flashback Table feature？ （）

• A、 RESETLOGS
• B、 TO TIMESTAMP
• C、 TO BEFORE DROP
• D、 RENAME TO
• E、 TO SCN

第2题：

In which scenario do you use the Flashback Database feature？（）

• A、 when a table is dropped and you restore it from the Recycle Bin
• B、 when a user’s schema is dropped and you recover the user’s schema
• C、 when some incorrect data is inserted in the table and you retrieve the table to a state that was at a certain timestamp
• D、 when a row of a table is updated frequently and committed， and you view all the versions of the row within a specific duration

第3题：

第4题：

Which two statements about subqueries are true?（）

• A、A single row subquery can retrieve data from only one table.
• B、A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.
• C、A SQL query statement can display data from table B that is referred to in its subquery, without including table B in its own FROM clause.
• D、A single row subquery can retrieve data from more than one table.
• E、A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.
• F、A multiple-row subquery cannot be used in a condition where the LIKE operator is used for comparison.

第5题：

Which two statements are correct regarding the Flashback Versions Query feature？（）

• A、 You can use this feature to identify the committed versions of the rows， but not the uncommitted versions.
• B、 You can use this feature to identify the versions of V$ views.
• C、 You can use this feature to identify the inserts， deletes， and updates performed on a particular row but not the data definition language （DDL） operations performed on the table.
• D、 You can use this feature for a table only if row movement is enabled for the table.
• E、 You can use this feature to identify the versions of external and fixed tables.

第6题：

Which three statements about subqueries are true? （）

• A、A main query can have more than one subquery.
• B、A subquery can have more than one main query.
• C、The subquery and main query must retrieve data from the same table.
• D、The subquery and main query can retrieve data from different tables.
• E、Only one column or expression can be compared between the subquery and main query.
• F、Multiple columns or expression can be compared between the subquery and main query.

第7题：

In which scenario will you use the Flashback Transaction Query feature？（）

• A、 when you want to restore an important table that is dropped from the Recycle Bin
• B、 when you want to obtain the SQL statements to undo the deletion of some important records from a table by a transaction
• C、when you want to restore a dropped user’s schema
• D、 when a row of a table is updated many times within a specific time period and you want all the versions of the row in the specified time period

第8题：

Which of the following statements best describes Flashback Versions Query？（）  

• A、 Flashback Versions Query is used to make changes to multiple versions of data that existed between two points in time.
• B、 Flashback Versions Query is used to view all version changes on rows that existed between the time  the query was executed and a point in time in the past.
• C、 Flashback Versions Query is used to view version changes and the SQL to undo those changes on rows that existed between two points in time.
• D、 Flashback Versions Query is used to view all version changes on rows that existed between two  points in time.

第9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

第10题：

In which scenario will you perform a user-managed incomplete recovery？（）

• A、 when a table is dropped and stored in the Recycle Bin
• B、when a table is dropped and purged from the Recycle Bin
• C、 when you are required to recover an existing table to its previous state
• D、 when you are required to view all the versions of a row of an existing table between a specific time period