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Which statement is true regarding Flashback Version Query？（）

题目
单选题
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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相似问题和答案

第1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.

正确答案:D

第2题：

Which statement is true regarding the INTERSECT operator?（）

  • A、It ignores NULL values 
  • B、Reversing the order of the intersected tables alters the result 
  • C、The names of columns in all SELECT statements must be identical 
  • D、The number of columns and data types must be identical for all SELECT statements in the query 

正确答案:D

第3题：

You plan to use Flashback Drop feature to recover a dropped table SALES_EMP. No other table with the same name exists in the schema.You query RECYCLEBIN and find multiple entries for the SALES_EMP table as follows, You then issue the following statement to recover the table:SQL> FLASHBACK TABLE sales_emp TO BEFORE DROP;What would be the outcome of the precedent statement?（）

A. It retrieves the latest version of the table from the recycle bin

B. It retrieves the oldest version of the table from the recycle bin

C. It retrieves the version of the table for which undo information is available

D. It returns an error because the table name is not specified as per the names in the OBJECT_NAME column


参考答案：A

第4题：

Which two statements are true regarding the ORDER BY clause? （）

  • A、It is executed first in the query execution 
  • B、It must be the last clause in the SELECT statement 
  • C、It cannot be used in a SELECT statement containing a HAVING clause
  • D、You cannot specify a column name followed by an expression in this clause 
  • E、You can specify a combination of numeric positions and column names in this clause

正确答案:B,E

第5题：

Which two statements are true regarding the ORDER BY clause? （）

  • A、The sort is in ascending by order by default.
  • B、The sort is in descending order by default.
  • C、The ORDER BY clause must precede the WHERE clause.
  • D、The ORDER BY clause is executed on the client side.
  • E、The ORDER BY clause comes last in the SELECT statement.
  • F、The ORDER BY clause is executed first in the query execution.

正确答案:A,E

第6题：

You are employed as a DBA in an organization. You are informed that the record of EMP_NO 1000 is missing from the SCOTT.EMP table. You are required to identify the user who deleted the record， the SQL statement that will undo the deletion， and the transaction ID of the transaction that deleted the employee record. Which feature will you use to perform the tasks？（）

  • A、 Only the Flashback Table
  • B、 Both the Flashback Transaction Query and the Flashback Version Query
  • C、 Only the Flashback Drop
  • D、 Only the Flashback Version

正确答案:B

第7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

正确答案:A

第8题：

Which statements are true regarding the Query Result Cache? ()

A. It can be set at the system, session, or table level.

B. It is used only across statements in the same session.

C. It can store the results from normal as well as flashback queries.

D. It can store the results of queries based on normal, temporary, and dictionary tables.


参考答案：A, C

第9题：

In order to perform Flashback Transaction Query operations， which of these steps are required？（）

  • A、 Ensure that database is running with version 10.1 compatibility.
  • B、 Enable Flashback Logging.
  • C、 Enable Supplemental Logging.
  • D、 Ensure that the database is running with version 10.0 compatibility.
  • E、 Ensure that the database is in ARCHIVELOG mode.

正确答案:C,D

第10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

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