CMS专题
单选题What is the correct order of steps to perform an online database backup？（） a. alter database begin backup b. alter database end backup c. Back up the database datafiles d. Back up the archive log files e. alter system switch logfileA a， b， c， d， eB e
题目
a， b， c， d， e
e， d， a， b， c
a， c， b， d， e
d， b， c， a， e
a， c， b， e， d
相似问题和答案
第1题：
What are the four steps， in their correct order， to mitigate a worm attack？（）
- A、contain，inoculate，quarantine，and treat
- B、inoculate，contain，quarantine，and treat
- C、quarantine，contain，inoculate，and treat
- D、preparation，identification，traceback，and postmortem
- E、preparation，classification，reaction，and treat
- F、identification，inoculation，postmortem，and reaction
正确答案:A
第2题：
Consider the recovery steps in each of the cases given below： Case 1： Shut down the database and perform a backup. Restore all the data files. Mount the database. Recover the database. Without applying all the redo log files， open the database using the RESETLOGS option. Back up the database. Case 2： Shut down the database and perform a backup. Restore only the data files of the tablespace where user error damaged the data. Mount the database. Recover the database. Open the database with the RESETLOGS option. Back up the database. Case 3： Shut down the database Restore the data files Open the database Perform recovery to the current point in time. Which case has the correct steps for an incomplete recovery？（）
- A、only case 1
- B、only case 2
- C、only case 3
- D、case 1 and 2
- E、case 2 and 3
- F、case 1 and 3
- G、all cases： case 1， case 2 and case 3
正确答案:A
第3题：
You are the administrator of a SQL Server 2000 computer. The server contains your company's order processing database. Two-hundred operators take orders by telephone 24 hours a day. Threehundred data entry personnel enter data from orders received by mail.
To ensure that order data will not be lost, your company's disaster recovery policy requires that backups be written to tape. Copies of these tapes must be stored at an off-site company location. Orders must be entered into the database before they can be filled. If the server fails, you must be able to recover the order data as quickly as possible.
You need to create a backup strategy that meets the company requirements and minimizes server workload. Which two actions should you take? (Each correct answer represents part of the solution. Choose two.)
A．Perform. a combination of full database and filegroup backups.
B．Perform. a combination of full database and file backups.
C．Perform. a combination of full database, differential, and transaction log backups.
D．Back up the data to a local tape drive.
E．Back up the data to a network share, and then use enterprise backup software to write the disk backups to tape.
解析：Explanation:
C: Most OLTP backup schemes include a full database, differential, and transaction log backups
E: In order to recover the data as quickly as possibly we backup the data to network share, and then backup that share to tape. This minimizes the impact of the backup process on the SQL Server computer.
Note 1: SQL Server 2000 provides three database recovery models. These are the Simple recovery model, the Full Recovery Model and the Bulk-Logged Recovery model. Simple Recovery requires the least administration. In the Simple Recovery model, data is recoverable only to the last full database or differential backup. Transaction log backups are not used, and consequently, minimal transaction log space is required.
This Recovery Model is not an appropriate choice for production systems where loss of recent changes is unacceptable. Full Recovery and Bulk-Logged Recovery models provide the greatest protection for data. These models rely on the transaction log to provide full recoverability and to prevent work loss in the broadest range of failure scenarios.
The Full Recovery model provides the most flexibility for recovering databases to an earlier point in time. The Bulk-Logged model provides higher performance and lower log space consumption for certain large-scale operations. It does this at the expense of some flexibility of pointin- time recovery. In this scenario we would want to implement the Full Recovery model as this Recovery model provides complete protection against media failure and provides the ability to recover the database to the point of failure or to a specific point in time.
To guarantee this degree of recoverability, all operations are fully logged. The backup strategy for full recovery consists of database backups, differential backups, which are optional, and transaction log backups. The differential backups are optional but have less of an effect on the system while they run, as they are smaller than full database backups.
This is because a differential backup creates a copy of all the pages in a database modified after the last database backup. A transaction log backup makes a copy only of the log file and backs up the changes made to the database after the last full or differential database backup. A log file backup cannot be used by itself to restore a database. A log file is used after a database restore to recover the database to the point of the original failure. The full database, differential, and transaction log backups can be written to a hard disk or other disk storage media such as a tape drive.
Disk backup devices can be defined on a local disk of a server or on a remote disk on a shared network resource. Tape backup devices are used in the same way as disk devices, with the exception that the tape device must be connected physically to the computer running an instance of SQL Server. SQL Server 2000 thus does not support backing up to remote tape devices.
Note 2, file backup, filegroup backup: SQL Server 2000 supports backing up or restoring individual files or filegroups within a database. This is a complex backup and the restore process that is usually reserved for large databases with high availability requirements. If the time available for backups is not long enough to support backing up the full database, subsets of the database can be backed up at different times. If a disk holding database files or filegroups fails, the site can restore just the lost files or filegroups. This allows for a quicker recovery because only the damaged files or filegroups are restored in the first step, not the entire database.
Incorrect Answers:
A: An OLTP server requires transaction log backups in order to be able to recover up to the point of failure.
B: An OLTP server requires transaction log backups in order to be able to recover up to the point of failure.
D: Backing up to a local tape device would minimize cost but it would compared to a backup to a network it would decrease performance of the server more, and it would take more time to recover.
第4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5题：
While performing LVM maintenance， the volume group datavg1 was exported and re-imported. The volume group is varied online， and the filesystems have been mounted. However， the database will not start. What action would most likely resolve this problem？（）
- A、 Perform a shown command on the VG device files.
- B、 Perform a syncvg to validate VG integrity.
- C、 Perform a redfinevg to correct the VGDA state.
- D、 Perform a synchlvodm to correct the LV ownership.
正确答案:A
第6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7题：
Network equipment supporting the use of flow control mechanisms has been recently installed. What is the purpose of flow control in a data network?（）
- A、It ensures that data is retransmitted if an acknowledgment is not received.
- B、It reassembles segments in the correct order on the destination device.
- C、It provides a mechanism for the receiver to control the transmission speed.
- D、It regulates the size of each datagram segment.
- E、All of the above are functions of flow control
正确答案:C
第8题：
A. It ensures that data is retransmitted if an acknowledgment is not received.
B. It reassembles segments in the correct order on the destination device.
C. It provides a mechanism for the receiver to control the transmission speed.
D. It regulates the size of each datagram segment.
E. All of the above are functions of flow control
第9题：
You are using RMAN to perform a closed database backup of your database. You issue these RMAN commands： STARTUP MOUNT； BACKUP FORMAT ’/BACKUP/df_%d_%s_%p.bus’ DATABASE filesperset = 2； Which components are included in the backup？（）
- A、Only the data files.
- B、Only the data files and the online logs.
- C、The data files， control files， and the online logs.
- D、The data files and control files， but not the online logs.
正确答案:D
第10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