多选题You are in the middle of a transaction and very crucial data has been modified. Because of a hardware failure， the instance has shut down before synchronizing all the database files. Which two statements are true？（）AOn startup， SMON coordinates instanc

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多选题

You are in the middle of a transaction and very crucial data has been modified. Because of a hardware failure， the instance has shut down before synchronizing all the database files. Which two statements are true？（）

On startup， SMON coordinates instance recovery.

On startup， CKPT coordinates instance recovery.

On startup， use RMAN to perform instance recovery.

Uncommitted changes will be rolled back after the database is opened.

On startup， perform media recovery and then instance recovery.

On startup， all the files will be synchronized and you get both committed and uncommitted data.

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第1题：

You are the administrator of a SQL Server 2000 computer. The server is configured as shown in the Database Server Configuration exhibit.

You need to create a new database named Inventory. Employees in your company will use the Inventory database to track inventory data. Users will require immediate responses to queries that help them locate where parts are stored. The tables in the database will be configured as shown in the Database Schema exhibit.

The database will consume 14 GB of disk space. You must configure the data files and transaction log to accelerate query response time.

Which two courses of action should you take? (Each correct answer represents part of the solution. Choose two.)

A. On drive C, create a transaction log.

On drive D, create a data file in the PRIMARY filegroup.

On drive E, create a data file in the SECONDARY filegroup.

B. On each drive, create a transaction log.

On each drive, create a data file in the PRIMARY filegroup.

C. On drive D, create a transaction log.

On drive E, create a data file in the PRIMARY filegroup.

D. On the PRIMARY filegroup, create all tables and all indexes.

E. On the PRIMARY filegroup, create all tables. On the SECONDARY filegroup, create all indexes.

F. On the PRIMARY filegroup, create the Parts table and its indexes.

On the SECONDARY filegroup, create all other tables and their indexes.

正确答案：AE
A,E 解析：Explanation:
A: The transaction log should be placed on a separate disk. A transaction log would not benefit of two or more disks since it is sequential. Create two data files on two separate physical disks would improve performance.

E: Separating the tables and the indexes improve performance for in particular joins.

Note: With SQL Server 2000 it is possible to create tables or indexes on specific filegroups. This allows us to control where the database's tables and indexes are physically located as filegroups can be placed on different hard drives. Placing tables in one filegroup and the table's nonclustered indexes in another filegroup on different physical disk can improve database performance because it will allow separate threads to access the tables and indexes.

However, a table and its clustered index cannot be separated into different filegroups as the clustered index determines the physical order of the data in the table. Furthermore, the transaction log should be placed on a physically separate disk. The transaction log file is written serially; therefore, using a separate, dedicated disk allows the disk heads to stay in place for the next write operation. This will further improve performance.

Incorrect Answers:
B: To improve performance, the transaction log should not be placed on the same physical disk that the tables or indexes are placed on. The transaction log file is written serially; therefore, placing it on a separate, dedicated disk allows the disk heads to stay in place for the next write operation and thus improves performance.

Furthermore, placing tables in one filegroup and the table's nonclustered indexes in another filegroup on different physical disk can improve database performance because it will allow separate threads to access the tables and indexes. However, a table and its clustered index cannot be separated into different filegroups as the clustered index determines the physical order of the data in the table.

C: The transaction log should be placed on a physically separate disk. The transaction log file is written serially; therefore, using a separate, dedicated disk allows the disk heads to stay in place for the next write operation. This will further improve performance. In this solution, the tables and their indexes are placed on the same disk. This solution thus does not take advantage of the performance improvements that can be realised through the correct utlization of the available hardware.

D: In this solution, the tables and their indexes are placed on the same disk. This solution thus does not take advantage of the performance improvements that can be realised through the correct utlization of the available hardware.

F: Greater performance gains can be realized by placing tables in one filegroup and the table’s nonclustered indexes in another filegroup on different physical disk. This will allow separate threads to access the tables and indexes.

第2题：

You work as a database administrator for Supportcenter.cn. One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）

A、Uses undo data for roll forward
B、Uses Flashback Log for recovery
C、Uses online redo logs to roll back
D、Uses undo data to roll back the transaction
E、Uses Recovery Manager （RMAN） to roll back
F、Uses the System Monitor （SMON） background process to perform instance recovery

正确答案:D

第3题：

You are the administrator of SQL Server 2000 computer named FABSQL2K01. You create a Data Transformation Services package that contains definition for two transform. data tasks.

The tasks gets data from two text files named Customers and Sales. The DTS package is configured as shown in the exhibit.

You do not want the DTS package to add any data to the server unless both transform. data tasks complete successfully.

You select the use transactions check box of DTS package and the Join transaction of present check box of both transform. data tasks. You then select the fail package on step failure check box of both transform. data tasks.

You want to use the DTS package to import data from the text files to the server. You want to ensure that changes are committed if all imported data is successfully transformed.

What should you do?

A．Select the commit on successful completion check box of the DTS package.

B．Select the commit transaction on successful completion of this step check box of the customers transform. data task.

C．Select the commit transaction on successful completion of this step check box of the sales transform. data task.

D．Select the commit transaction on successful completion of this step check box of both transform. data tasks.

正确答案：A
解析：Explanation:ItispossibletosettheCommitonsuccessfulpackagecompletioncheckboxontheAdvancedTaboftheDTSPropertiesdialogBox.ThischeckboxspecifiesthatifeachindividualSQLstatementisatransactioncompletessuccessfully,thetransactionwillautomaticallybecommitted;andifthestatementhasanerror,thestatementisrolledback.Whenthischeckboxiscleared,theDTSconnectionsoperateinimplicittransactionmodeandthefirstSQLstatementbeginsatransactionthatremainsineffectuntilDTScommitsitorrollsitback.ThenextSQLstatementexecutedafteranycommitorrollbackstartsanewtransaction.IncorrectAnswers:B:TheCommittransactiononsuccessfulcompletionofthisstepcheckboxtreatseachstepinaDTSpackageasseparate.Thus,selectingtheCommittransactiononsuccessfulcompletionofthisstepcheckboxofthecustomerstransform.datataskwouldresultinthistaskbeingcommittedregardlessoftheprogressofthesalestransformationdatatask.C:TheCommittransactiononsuccessfulcompletionofthisstepcheckboxtreatseachstepinaDTSpackageasseparate.Thus,selectingCommittransactiononsuccessfulcompletionofthisstepcheckboxofthesalestransform.datataskwouldresultinthistaskbeingcommittedregardlessoftheprogressofthecustomer’stransformationdatatask.D:TheCommittransactiononsuccessfulcompletionofthisstepcheckboxtreatseachstepinaDTSpackageasseparate.Thus,selectthecommittransactiononsuccessfulcompletionofthisstepcheckboxofbothtransform.datataskswouldresultinthetwopartsbeingtreatedasseparateandeachpartbeingcommittedregardlessoftheprogressintheother.

第4题：

One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）

A、uses undo data for roll forward
B、uses Flashback Log for recovery
C、uses online redo logs to roll back
D、uses undo data to roll back the transaction
E、uses Recovery Manager （RMAN） to roll back
F、uses the System Monitor （SMON） background process to perform instance recovery

正确答案:D

第5题：

You are designing a Windows Azure application that will use Windows Azure Table storage. You need to recommend an approach for minimizing storage costs. What should you recommend？（）

A、 Use Entity Group Transactions.
B、 Use multiple partitions to store data.
C、 Use a transaction scope to groupall storage operations.
D、 Use Microsoft Distributed Transaction Coordinator （MSDTC）.

正确答案:A

第6题：

Which of the following data network would you implement if you wanted a wireless network that had a relatively high data rate, but was limited to very short distances?（）

A、Broadband personal comm. Service (PCS)
B、Broadband circuit
C、Infrared
D、Spread spectrum
E、Cable

正确答案:C

第7题：

A、On startup， SMON coordinates instance recovery.
B、On startup， CKPT coordinates instance recovery.
C、On startup， use RMAN to perform instance recovery.
D、Uncommitted changes will be rolled back after the database is opened.
E、On startup， perform media recovery and then instance recovery.
F、On startup， all the files will be synchronized and you get both committed and uncommitted data.

正确答案:A,D

第8题：

You are the administrator of a SQL Server 2000 computer. You are configuring a database for an inventory application. The hard disks on your server are configured as shown in the exhibit.

The operating system files are located on drive C. Your database will store a maximum of 6 GB of data and requires a maximum of 2 GB of disk space for the transaction log.

You want to optimize database performance. What should you do?

A．Add a 2-GB transaction log to drive D, a 3-GB data file to drive E, and a 3-GB data file to drive F

B．Add a 1-GB transaction log to drive C, a 1-GB transaction log to drive D, a 3-GB data file to drive E, and a 3-GB data file to drive F

C．Add a 1-GB transaction log to drive E, a 1-GB transaction log to drive F, a 3-GB data file to drive E, and a 3-GB data file to drive F

D．Add a 2-GB transaction log to drive F, a 3-GB data file to drive D, and a 3-GB data file to drive E

正确答案：D
解析：Explanation: Basically there are two methods to improve performance in this scenario:

Method 1: put the transaction log file on a separate physical disk.
One way to improve performance and recoverability of your database is to place the data files and the transaction log files on separate disk subsystems, and to use dedicated disks for your data files so that data read and write (I/O) requests are not competing with other I/O requests on those disks. This is (A).

Method 2: data files split across two physical disks
Splitting your data files among a number of disks results in increased I/O performance in particular when multiple controllers are used like in this scenario. This is (D).

To decide which is better we must think about the application. This is an inventory system and we can assume that the queries would be more frequent than additions and update of rows. So we should choose method 2 since it gives the best performance for reading data.

Note: Physical database design involves mapping the logical design onto physical media to allow for the data to be physically accessed and maintained as quickly as possible by taking advantage of the available hardware and software features.

It is important to correctly design the database and to take advantage of hardware and software features early in the development cycle of a database application, because making changes to these components at a later stage it is difficult. Placing log files and the data files on different physical disks, and placing the log file of a drive that does not hold the operating system can improve database performance as it allows the frequently written to log file to exist a disk with its own read/write heads.

Incorrect Answers:
A: In an inventory system data is read more frequently and not so many changes are made to the database. We should optimize the data files not the log file.

B: Placing log files and the data files on different physical disks and placing the log file of a drive that does not hold the operating system can improve database performance as it allows the frequently written to log file to exist a disk with its own read/write heads. In this part of the log file is placed on drive C, which would also hold the operating system.

C: Placing log files and the data files on different physical disks can improve database performance as it allows the frequently written to log file to exist a disk with its own read/write heads. In this solution the log file and the data file are placed on the same physical drive.

第9题：

You are in the middle of a transaction updating a very important table. The machine on which a database wasrunning reboots because of power outage. This caused a database instance failure. Which statement is true inthis situation（）

A、The online redo log files and archived redo log files are required to accomplish the recovery.
B、The uncommitted transaction will be committed at the next startup of the database instance.
C、The uncommitted transaction is rolled back automatically at the next opening of the database.
D、The DBA has to perform the recovery on the database to recover the uncommitted transaction

正确答案:C

第10题：

You work as a database administrator for Certkiller .com. In the middle of a transaction， a user session was abnormally terminated but the instance is still up and the database is open. Which two statements are true in this scenario？（）

A、Event Viewer gives more details on the failure.
B、The alert log file gives detailed information about the failure.
C、PMON rolls back the transaction and releases the locks.
D、SMON rolls back the transaction and releases the locks.
E、The transaction is rolled back by the next session that refers to any of the blocks updates by the failed transaction.
F、Data modified by the transaction up to the last commit before the abnormal termination is retained in the database.

正确答案:C,F

You are in the middle of a transaction and very crucial data

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