Oracle Oracle Certifications 1Z0-053 Questions & Answers

• Question 181:

  What methods of point-in-time recovery are available? (Choose all that apply.)

  A. Change-based

  B. Cancel-based

  C. Time-based

  D. Sequence number-based

  E. Transaction number-based

  Correct Answer: ABCD

• Question 182:

  Which files are required for a full recovery of the database in ARCHIVELOG mode? (Choose three.)

  A. Database datafiles

  B. Online redo logs

  C. Archived redo logs

  D. Backup control file

  E. Control file from a backup

  Correct Answer: ACD

• Question 183:

  Upon starting your database, you receive the following error:

  SQL> startup ORACLE instance started. Total System Global Area 171581440 bytes Fixed Size 1298640 bytes Variable Size 146804528 bytes Database Buffers 20971520 bytes Redo Buffers 2506752 bytes Database mounted.

  ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/oracle01/oradata/orcl/redo01.log' ORA-00312: online log 1 thread 1: '/oracle01/oradata/orcl/redo01a.log'

  You can choose from the following steps: a: Restore the database datafiles.

  b: Issue the alter database clear unarchived logfile group 1 command.

  c: Issue the alter database open command.

  d: Issue the alter database open resetlogs command.

  e: Recover the database using point-in-time recovery.

  f: Issue the Startup Mount command to mount the database.

  g: Back up the database.

  Which is the correct order of these steps in this case?

  A. a, f, e, d, g

  B. f, e, d

  C. f, b, c, g

  D. a, f, c

  E. The database cannot be recovered.

  Correct Answer: C

  1.

  one step of process must be ALTER DATABASE OPEN, since the database instance is started and mounted from clean shutdown.

  2.

  After redo log clear done, you must backup the database immediately, so that you have a backup you can use for complete recovery without relying on the cleared log group.

• Question 184:

  You have lost all your database control files. To recover them, you are going to use the results of the alter database backup controlfile to trace command. Your datafiles and your online redo logs are all intact.

  Which of the following is true regarding your recovery?

  A. You will need to open the database with the resetlogs command.

  B. All you need to do is execute the trace file from SQL*Plus and it will perform the recovery for you.

  C. You will use the resetlogs version of the create controlfile command.

  D. You will use the noresetlogs version of the create controlfile command.

  E. You will use the trace file to create a backup control file, and then you will recover the database with the recover database using backup controlfile command

  Correct Answer: D

  Refer to here CREATE CONTROLFILE Using NORESETLOGS Example The following CREATE CONTROLFILE statement is generated by an ALTER DATABASE BACKUP CONTROLFILE TO TRACE statement for a database with Oracle managed data files and redo log files:

  CREATE CONTROLFILE

  

• Question 185:

  In your test database:

  You are using Recovery Manager (RMAN) to perform incremental backups of your test database

  The test database is running in NOARCHIVELOG mode

  One of the data files is corrupted

  All online redo log files are lost because of a media failure

  Which option must you consider in this scenario?

  A. Configuring the database in ARCHVIELOG mode and then using incremental backup to recover the database

  B. Using incremental backup to recover the damaged data file and then manually creating the online redo log files

  C. Creating a new test database because the database is not recoverable due to the fact that the database is configured in NOARCHIVELOG mode

  D. Using incremental backups to recover the database by using the RECOVER DATABASE NOREDO command and then using the RESETLOGS option to open the database.

  Correct Answer: D

  Example 3-6 Recovering a NOARCHIVELOG Database

  You can perform limited recovery of changes to a database running in NOARCHIVELOG mode by applying incremental backups. The incremental backups must be consistent, like all backups of a database run in NOARCHIVELOG mode, so

  you cannot back up the database when it is open.

  Assume that you run database prod in NOARCHIVELOG mode with a recovery catalog. You shut down the database consistently and make a level 0 backup of database prod to tape on Sunday afternoon. You shut down the database

  consistently and make a level 1 differential incremental backup to tape at 3:00 a.m. on Wednesday and Friday. On Saturday, a media failure destroys half the data files and the online redo logs. Because the online logs are lost, you must

  specify the NOREDO option in the RECOVER command. Otherwise, RMAN searches for the redo logs after applying the Friday incremental backup and issues an error message when it does not find them.

  After connecting RMAN to prod and the catalog database, recover as follows:

  STARTUP FORCE NOMOUNT;

  RESTORE CONTROLFILE; # restore control file from consistent backup ALTER DATABASE MOUNT;

  RESTORE DATABASE; # restore data files from consistent backup RECOVER DATABASE NOREDO; #

  specify NOREDO because online redo logs are lost

  ALTER DATABASE OPEN RESETLOGS;

  The recovered database reflects only changes up through the time of the Friday incremental backup.

  Because there are no archived redo log files, there is no way to recover changes made after the incremental backup.

• Question 186:

  Which of the following represents the correct way to perform an online recovery of datafile 4, which is assigned to a tablespace called USERS?

  A. shutdown restore datafile 4; recover datafile 4; alter database open;

  B. Sql alter database datafile 4 offline; restore datafile 4; recover datafile 4; alter database open;

  C. Sql alter database datafile 4 offline; restore datafile 4; Sql alter database datafile 4 online;

  D. Sql alter database datafile 4 offline; restore database datafile 4; recover database datafile 4; Sql alter database datafile 4 online;

  E. Sql alter database datafile 4 offline; restore datafile 4; recover datafile 4; Sql alter database datafile 4 online;

  Correct Answer: E

• Question 187:

  Which are the correct steps, in order, to deal with the loss of an online redo log if the database has not yet crashed?

  a: Issue a checkpoint.

  b: Shut down the database.

  c: Issue an alter database open command to open the database.

  d: Startup mount the database.

  e: Issue an alter database clear logfile command.

  f:

  Recover all database datafiles.

  A.

  a, b, c, d

  B.

  b, d, e, c

  C.

  a, b, d, e, c

  D.

  b, f, d, f, c

  E.

  b, d, a, c

  Correct Answer: C

• Question 188:

  The database Is configured in ARCHIVELOG mode. The database needs to be up 24 X 7. You want to perform user managed backup for the data files of the HR_DATA tablespace. To accomplish the task, you issued the following command:

  SQL> ALTER TABLESPACE hr_data BEGIN BACKUP;

  Which two statements are true in this scenario? (Choose two.)

  A. No transaction on the tablespace is allowed but you can perform queries.

  B. The tablespace will automatically come out of backup mode when the file copy is complete.

  C. The checkpoint change number is frozen in headers of the data files until the file is removed from backup mode.

  D. The database writes the before image of an entire block to the redo stream before modifying. block tor the first time.

  Correct Answer: CD

  Making User-Managed Backups of Online Read/Write Tablespaces You must put a read/write tablespace in backup mode to make user-managed data file backups when the tablespace is online and the database is open. The ALTER TABLESPACE ... BEGIN BACKUP statement places a tablespace in backup mode. In backup mode, the database copies whole changed data blocks into the redo stream. After you take the tablespace out of backup mode with the ALTER TABLESPACE ... END BACKUP or ALTER DATABASE END BACKUP statement, the database advances the data file checkpoint SCN to the current database checkpoint SCN.

  When restoring a data file backed up in this way, the database asks for the appropriate set of redo log files to apply if recovery is needed. The redo logs contain all changes required to recover the data files and make them consistent.

• Question 189:

  A database is running In ARCHIVELOG mode. It has two online redo log groups and each group has one member.

  A LGWR Input/output (I/O) fells due to permanent media failure that has resulted In the loss of redo log file and the LWGR terminates causing the instance to crash. The steps to recover from the loss of a current redo log group member in the

  random order are as follow.

  1) Restore the corrupted redo log group.

  2) Restore from a whole database backup.

  3) Perform incomplete recovery.

  4) Relocate by renaming the member of the damaged online redo log group to a new location.

  5) Open the database with the RESETLOGS option.

  6) Restart the database instance.

  7) Issue a checkpoint and clear the log.

  Identify the option with the correct sequential steps to accomplish the task efficiently.

  A. 1, 3, 4, and 5

  B. 7, 3, 4. and 5

  C. 2, 3, 4, and 5

  D. 7, 4, 3. and 5

  E. Only 6 is required

  Correct Answer: C

  Recovering After Losing All Members of an Online Redo Log Group If a media failure damages all members of an online redo log group, then different scenarios can occur depending on the type of online redo log group affected by the failure and the archiving mode of the database.

  If the damaged online redo log group is current and active, then it is needed for crash recovery; otherwise, it is not. Table 30-4 outlines the various recovery scenarios.

  

• Question 190:

  You have backed up your database using image copies. You have lost the SYSTEM tablespace and need to restart your database as quickly as possible. What is the correct solution?

  A. Restore the SYSTEM tablespace from the last backup set and then recover the database.

  B. Restore the SYSTEM tablespace image copy using the restore command and then restore the database.

  C. Use the switch datafile command to instantly switch to the datafile copy, recover the tablespace, and open the database.

  D. The database is not recoverable in this situation with image copies.

  E. Manually copy the datafile image copy to the correct location and then manually restore the database from SQL*Plus.

  Correct Answer: C