多选题When a database administrator chooses the dimensions for an MDC table, which two characteristics should beconsidered?()Athe query transaction rateBnumeric data versus character dataCextent sizeDthe cardinality of the candidate columnsEprefetch size

题目
多选题
When a database administrator chooses the dimensions for an MDC table, which two characteristics should beconsidered?()
A

the query transaction rate

B

numeric data versus character data

C

extent size

D

the cardinality of the candidate columns

E

prefetch size

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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:

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

正确答案:E

第3题:

You are the administrator of a SQL Server 2000 database. You import a table of geographic information from a Microsoft access database into a SQL Server 2000 database. The table has 12,000 rows. Each row averages 5,000 bytes. The table contains lockup data that does not change.

You want to minimize the size of the data file and the time required to back up the data. Which two actions should you take? (Each correct answer presents part of the solution. Choose two)

A. Create a 60-MB data file named geography.ndf

B. Create a 95-MB data file named geography.ndf

C. Create a 60-MB data file named geography.mdf

D. Create a 95-MB data file named geography.mdf

E. Place the table in the PRIMARY filegroup.

F. Place the table in a new filegroup named LOCATION.


正确答案:BF
B,F 解析:Explanation: As SQL Server 2000 supports backing up or restoring individual files or file groups within a database, it is possible to reduce back up time by creating a separate data file table so that only that table will be backed up. This separate data file will have to be a secondary data file because a database can only have one primary data file, which is identified by the .mdf extension, it is the starting point of the database and locates all the other files in the database. Secondary data files are identified by the .ndf extension and comprise all of the data files except the primary data file. A database need not have a secondary data file and it is also possible to create multiple secondary data files on database.

Rows are stored in data pages. Rows cannot cross different data pages. The size of data page in SQL Server 2000 (or SQL 7.0) is 8,192 bytes. We can only store one row in every data page in this scenario. Thus, to estimate the size of the tale we would need to multiply the number of rows, 12,000 in this scenario, by 8,192 bytes. This will give us a table size of 98,304,000 bytes. As computer data storage is calculated using the binary rather than the decimal system, there is 1,024 bytes per Kb and 1,024 Kb per MB, rather than 1,000 bytes per Kb and 1,000 Kb per MB, we thus require a database size of at least 93.75 MB.

Incorrect Answers:
A: The data size of this table is insufficient as a minimum size of 93.75 MB is required.

C: The data size of this table is insufficient as a minimum size of 93.75 MB is required. Furthermore, the .mdf file extension indicate in this solution implies that the data file will be placed in the primary filegroup. It would thus not be possible to backup the data file pertaining to the table only.

D: The .mdf file extension indicate in this solution implies that the data file will be placed in the primary filegroup. It would thus not be possible to backup the data file pertaining to the table only.

E: As SQL Server 2000 supports backing up or restoring individual files or file groups within a database, it is possible to reduce back up time by creating a separate data file table so that only that table will be backed up. This separate data file will have to be a secondary data file because a database can only have one primary data file, which is identified by the .mdf extension, it is the starting point of the database and locates all the other files in the database.

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:

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6题:

When a database administrator chooses the dimensions for an MDC table, which two characteristics should beconsidered?()

  • A、the query transaction rate 
  • B、numeric data versus character data  
  • C、extent size  
  • D、the cardinality of the candidate columns  
  • E、prefetch size 

正确答案:C,D

第7题:

You work as a database administrator for Certkiller .com. In your transaction application, you have scheduled a job to update the optimizer statistics at05:00 pm every Friday. The job has successfully completed. Which three pieces of information would you check to confirm that the statistics have been collected?()

  • A、Average row size
  • B、Last analyzed date
  • C、Size of table in bytes
  • D、Size of table in database blocks
  • E、Number of free blocks in the free list
  • F、Number of extents present in the table.

正确答案:A,B,D

第8题:

You are the administrator of two Microsoft Windows 2000 advanced server computers. On these servers, you are configuring a database that will store accounting information for your company.

The data must be available at all times. Interruptions in data connectivity should not last longer than five minutes. Any changes to the database should not require you to reconfigure the client computers.

How should you configure the database?

A.Configure the database on the two servers as a SQL Server 2000 cluster.

B.Configure the database on one server, and then configure a standby database on the second server.

C.Configure the database on each server. Use Microsoft Distributed Transaction Coordinator to keep the two servers perfectly synchronized.

D.Configure the database as a federated database, and then partition half the data on each server.


正确答案:A
解析:Explanation: SQL Server 2000 failover clustering provides high availability support by allowing us to configure one failover cluster to automatically, with no manual configuration, fail over to any other node in the failover cluster configuration. In this way, we minimize system downtime and provide high server availability during an operating system failure or a planned upgrade. Before SQL Server 2000 failover clustering can be set up, we must install Windows NT 4.0, Enterprise Edition, Windows 2000 Advanced Server or Windows 2000 Datacenter Server, and the Microsoft Cluster Service (MSCS).

In this scenario a cluster would be preferred to a standby server because it would be available immediately. A standby server on the other would require manual configuration and more time to become online.

Incorrect Answers:
B: A standby server would require you to reconfigure clients to allow it to connect to the standby server when the main server goes down. It would require at least several minutes of manual administration before the standby server would be operational. But the scenario requires that no reconfiguration of the client computers should be necessary. Therefore we should use a SQL Server 2000 cluster not a standby server.

Note: A standby server is a second server that contains a copy of the databases on the primary server and that can be brought online in the event of a primary server failure or due to scheduled maintenance on the primary server. This allows users to continue working with databases when the primary server becomes unavailable. When the primary server becomes available again, any changes to the standby server's copies of databases must be restored back to the primary server.

C: The Microsoft Distributed Transaction Coordinator coordinates distributed transactions, but would not increase availability.

Note: The Microsoft Distributed Transaction Coordinator (MS DTC) is a transaction manager that allows client applications to include several different sources of data in one transaction. MS DTC coordinates committing the distributed transaction across all the servers enlisted in the transaction.

An installation of SQL Server 2000 can participate in a distributed transaction by calling stored procedures on remote servers running SQL Server, automatically or explicitly promoting the local transaction to a distributed transaction and enlist remote servers in the transaction, and making distributed updates that update data on multiple OLE DB data sources. If these OLE DB data sources support the OLE DB distributed transaction interface, SQL Server 2000 can also enlist them in the distributed transaction. The MS DTC service coordinates the proper completion of the distributed transaction to ensure that either all of the updates on all the servers are made permanent, or, in the case of errors, all erased.

D: With Federated SQL Server 2000 servers, SQL Server 2000 databases can be spread across a group of autonomous database servers. These are capable of supporting the processing growth requirements of the largest Web sites and enterprise data-processing systems built with Microsoft Windows DNA, which divides the processing units of a data processing system into logical tiers. This however does not improve availability.

第9题:

You are working on an Oracle Database 10g database. For which purposes would you use the Flashback Transaction Query feature? ()

  • A、 To recover a dropped table.
  • B、 To recover a dropped schema.
  • C、 To recover data from a truncated table.
  • D、 To view changes made by all the transactions during a given period of time.
  • E、 To view changes made by a single transaction during a given period of time.

正确答案:D,E

第10题:

You work as a database administrator at Certkiller .com. 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 EMPLOYEEStable. 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

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