多选题On which two database objects can the VERSIONS clause of the Flashback Versions Query be used？（）Afixed tablesBheap tablesCexternal tablesDtemporary tablesEIndex-Organized Tables （IOTs）

第1题：

Your Oracle Database 10g is online when you execute the following statement：        SQL>ALTER TABLESPACE MY_TABLESPACE FLASHBACK OFF；   What is the result of executing this statement if the Flashback Database feature is already enabled in the database？（）

• A、 The database does not record flashback logs for MY_TABLESPACE
• B、 The tables residing in MY_TABLESPACE are not protected by the Recycle Bin.
• C、 All the tablespaces except MY_TABLESPACE can be recovered using Flashback Database feature.
• D、 None of the flashback technologies， such as Flashback Table， Flashback Transaction Query and Flashback Version Query can be used to recover individual rows within the objects from MY_TABLESPACE

第2题：

By mistake， you ran the batch job （for updating the BILL_DETAILS table） twice. You are not sure which rows in the BILL_DETAILS table were affected. You need to identify：  a） a list of changes made along with the transaction identifier of each change  b） the necessary SQL statements to undo the erroneous changes  Which option would you choose？（）

• A、RMAN only
• B、Flashback Table only
• C、Flashback Versions Query only
• D、Flashback Database and Flashback Transaction Query
• E、Flashback Versions Query and Flashback Transaction Query

第3题：

You are maintaining your OLTP database in Oracle10g. You are performing the Flashback Transaction Query to find the undo SQL statements that can be used to undo the changes made to the database in the specific time period. Which pseudocolumn will you use to perform the Flashback Transaction Query？（）

• A、 VERSIONS_STARTSCN
• B、 VERSIONS_STARTTIME
• C、 VERSIONS_XID
• D、 VERSIONS_OPERATION

第4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5题：

Which two statements are true regarding the USING and ON clauses in table joins?（）

• A、Both USING and ON clauses can be used for equijoins and nonequijoins 
• B、Amaximum of one pair of columns can be joined between two tables using the ON clause 
• C、The ON clause can be used to join tables on columns that have different names but compatible data types 
• D、The WHERE clause can be used to apply additional conditions in SELECT statements containing the ON or the USING clause 

第6题：

Which pseudocolumn could you use to identify a unique row in a Flashback Versions Query？（）

• A、 XID
• B、 VERSIONS_PK
• C、 VERSIONS_XID
• D、 VERSIONS_UNIQUE

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第13题：

Which two statements are true about WHERE and HAVING clauses? （）

• A、A WHERE clause can be used to restrict both rows and groups.
• B、A WHERE clause can be used to restrict rows only.
• C、A HAVING clause can be used to restrict both rows and groups.
• D、A HAVING clause can be used to restrict groups only.
• E、A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.
• F、A HAVING clause CANNOT be used in subqueries.

第14题：

On which two database objects can the VERSIONS clause of the Flashback Versions Query be used?（）

• A、fixed tables
• B、heap tables
• C、external tables
• D、temporary tables
• E、Index-Organized Tables (IOTs)

第15题：

Which of the following can be used in conjunction with a Flashback Versions Query to filter the results？（）

• A、 A range of SCN values
• B、 A list of SCN values
• C、 A starting and ending timestamp
• D、 Minimum and maximum sequence values
• E、 A list of sequence values

第16题：

For which two database objects can the VERSIONS clause of the Flashback Versions Query be used?（）(Choose two.)

• A、views
• B、fixed tables
• C、heap tables
• D、external tables
• E、temporary tables
• F、index-organized tables (IOT)

第17题：

Which statement is true regarding Flashback Version Query？ （）

• A、 It returns versions of rows only within a transaction.
• B、 It can be used in subqueries contained only in a SELECT statement.
• C、 It will return an error if the undo retention time is less than the lower bound time or SCN specified.
• D、 It retrieves all versions including the deleted as well as subsequently reinserted versions of the rows.

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