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databases Online Quiz - 138

Description: databases Online Quiz - 138
Number of Questions: 20
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Tags: databases
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When performing an incomplete recovery of the whole database, what must be true about the data files that are restored ?

  1. All of the data files must be from a backup taken prior to the point in time to which you want to recover.

  2. Only the data files belonging from the SYSTEM tablespace must be from a backup taken prior to the point in time to which you want to recover.

  3. Only the data files that need recovery must be from a backup taken prior to the point in time which you want to recover.

  4. Only the data files belonging to the SYSTEM tablespace and the data files that need recovery must be from a backup taken prior to the point in time to which you want to recover.


Correct Option: A

You have performed the first step in placing your database into ARCHIVELOG mode. The second step is deciding whether the online redo log files are to be archived automatically or manually. which action should you take to enable archiving an instance startup?

  1. Set the LOG_ARCHIVE_START parameter to TRUE in the initialization parameter file.

  2. Automatic archive is the default when ARCHIVELOG mode is set. No further actions are required.

  3. Set the LOG_ARCHIVE_MAX_PROCESSES parameter to n (where n is the number of Archiver process) in the initialization parameter file.

  4. Immediately after setting the database in ARCHIVELOG mode, in SQL*Plus select automatic archiving using the syntax : ALTER DATABASE SET LOG_ARCHIVE_START=TRUE


Correct Option: A

Which statement is ture regarding checkpoints and recovery ?

  1. A checkpoint defines the highest system change number (SCN)

  2. All redo entries higher or at the SCN are known to be written to the data files.

  3. Only the redo records containing SCNs higher then the checkpoint need to be applied during recovery.

  4. The LOG_CHECKPOINT_INTERVAL initialization paramter specifies the amount of time beteen incremental checkpoints.


Correct Option: C

A user is running a long update batch file. Many tables are updated and all the statements are in one transaction. Before the process is finished, the user machine lost power. When the user calls you, what should you do as DBA?

  1. Do nothing, the PMON process handles everything.

  2. Shut down the database and restore all the tables the user was updating.

  3. Log in as DBA, clean up the partial updates in those tables, and do another manual backup.

  4. Use LogMiner to find out which records are changed based on the user’s ID, then roll back all those changes.


Correct Option: A

You issue this statement ALTER DATABASE BACKUP CONTROLFILE TO TRACE; What does the statment generate ?

  1. A text copy of the control file.

  2. A binary copy of the control file.

  3. A file containing a SQL statement which will re-create the database.

  4. A file containing a SQL statement which will re-create the control file.


Correct Option: D

Which statement is true regarding RMAN components?

  1. Each target database requires its own recover catalog.

  2. RMAN scripts can be stored in the recovery catalog or the targer control file.

  3. A channel is a stream of data to a device type and corresponds to one server session.

  4. The RMAN executable interprets server session commands and establishes connections to the target database.


Correct Option: C
  1. The contents and data files belonging to the IND2 tablespace are dropped.

  2. The statement will only succeed if the IND2 tablespace was built using Oracle-Managed Files (OMF) data files.

  3. The statement will only succeed if the data files belonging to the IND2 tablespace are Oracle Managed Files (OMF) or of the database was created using OMF.

  4. The contents of the tablespace are dropped along with all its data files except those identical with Oracle-Managed Files (OMF) naming convention.


Correct Option: A

Your database is running in NOARCHIVELOG mode. Every night there is a backup taken using RMAN. During your startup this morning you received an error regarding DISK 3 on your server.This is the location of your data file for the SYSTEM tablespace. Which option is open to you?

  1. The data file needs to be restored by using operating system commands, because a data file movement must take place, and then the database can be recovered from RMAN.

  2. The data file needs to be restored by using operating system commands, since a data file movement must take place, and then the database must be recovered manually.

  3. From RMAN you can issue the commands RESTORE and RECOVER. RMAN automatically restores the data file on DISK 3 to another disk, based upon utilization statistics.

  4. From RMAN you can issue a SET NEWNAME command to update the data file location information in the control file, and then issue the RESTORE and RECOVER commands to recover the database.


Correct Option: D

Consider this RMAN command: RMAN> CONFIGURE RETENTION POLICY CLEAR; What is the effect of this command?

  1. Backups will never expire.

  2. It removes any retention policy.

  3. The DELETE OBSOLETE command will fail with an error.

  4. It sets the retention policy to the default of REDUNDANCY 1.


Correct Option: D

You have just run this syntax to start the listener from the Listener Control utility: LSNRCTL>START Starting /mstgelai/oracle/bin/tnslsnr: please wait... System parameter file is /u01/oracle/network/admin/listener.ora Log messages written to /u01/oracle/network/log/listener.log Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=stc-sun01-server)(PORT=1521))) Connecting to... The command completed successfully What is the name of the Listener you started?

  1. TNSLSNR

  2. LISTENER

  3. LOCAL_LISTENER

  4. DEFAULT_LSRN


Correct Option: B

A tablespace has a table with 30 extents in it. Is this bad?

  1. True

  2. False


Correct Option: B

If you see a pin hit ratio of less than 0.8 in the estat library cache report is this a problem?

  1. True

  2. False


Correct Option: B

AI Explanation

To answer this question, let's first understand what a "pin hit ratio" is in the context of the estat library cache report.

In the Oracle database, the library cache is a shared area in memory that stores SQL statements, execution plans, and other database objects. The pin hit ratio is a metric that measures the efficiency of the library cache in handling pinned objects.

A pinned object is an object that is currently being used or referenced by a session. When an object is pinned in the library cache, it remains in memory and cannot be aged out or flushed. The pin hit ratio is the ratio of the number of times a pinned object is found in the library cache to the number of times it is requested.

Now, let's evaluate the statement: "If you see a pin hit ratio of less than 0.8 in the estat library cache report, is this a problem?"

Option A) True - This option is incorrect. A pin hit ratio of less than 0.8 does not necessarily indicate a problem. While a higher pin hit ratio is generally desirable, the specific threshold for what is considered a problem can vary depending on the system and workload.

Option B) False - This option is correct. A pin hit ratio of less than 0.8 does not necessarily indicate a problem. It is important to consider the overall performance and behavior of the system, as well as other relevant metrics, before determining if there is a problem with the library cache.

The correct answer is B) False. A pin hit ratio of less than 0.8 in the estat library cache report does not automatically indicate a problem. It is just one metric that should be considered along with other factors when evaluating the performance of the library cache.

A tablespace has a table with 30 extents in it. Is this bad?

  1. True

  2. False


Correct Option: B

If you see a pin hit ratio of less than 0.8 in the estat library cache report is this a problem?

  1. True

  2. False


Correct Option: B

When performing recovery of a database in NOARCHIVELOG mode with RMAN, the target database must be in the ______ state to restore the control file.

  1. OPEN

  2. IDLE

  3. MOUNT

  4. NOMOUNT


Correct Option: D

An Oracle instance is executing in a nondistributed configuration. The instance fails because of an operating system failure. Which background process would perform the instance recovery when the atabase is reopened ?

  1. PMON

  2. SMON

  3. RECO

  4. ARCn

  5. CKPT


Correct Option: B

AI Explanation

To answer this question, you need to understand the role of the different background processes in an Oracle database.

Option A) PMON - PMON (Process Monitor) is responsible for process cleanup and process recovery. It is not involved in instance recovery.

Option B) SMON - SMON (System Monitor) is responsible for instance recovery. When an instance fails and is restarted, SMON performs crash recovery to bring the database to a consistent state.

Option C) RECO - RECO (Recoverer) is responsible for distributed transaction recovery. It is not involved in instance recovery.

Option D) ARCn - ARCn (Archiver) is responsible for archiving redo log files. It is not involved in instance recovery.

Option E) CKPT - CKPT (Checkpoint) is responsible for signaling the database writer (DBWn) to write dirty buffers to disk and update the checkpoint position in the control file. It is not involved in instance recovery.

The correct answer is B) SMON. SMON performs instance recovery when the database is reopened after an instance failure. It ensures that the database is brought to a consistent state by applying the necessary redo logs.

Therefore, the correct answer is B) SMON.

CREATE TABLESPACE user_data DATAFILE '/u01/oradata/user_data_01.dbf' SIZE 100M LOCALLY MANAGED UNIFORM SIZE 1M AUTOMATIC SEGMENT SPACE MANAGEMENT; Which part of the tablespace will be of a uniform size of 1 MB?

  1. Extent

  2. Segement

  3. Oracle block

  4. Operating system block


Correct Option: A

The ORDERS table has a constant transaction load 24 hours a day, so down time is not allowed. The index become fragmented. Whic statment is true ?

  1. The index need to be dropped, and then re-created.

  2. The resolution of index fragmentation depends on the type of index.

  3. The index can be rebuilt while users continue working on the table.

  4. The fragmented can be ignored because Oracle resolve index fragmentation by means of a freelist.

  5. The index can be rebuilt, but users will not have access to the index during this time.


Correct Option: C

You omit the UNDO tablespace clause in your CREATE DATABASE statment. The UNDO_MANAGEMENT parameter is set to AUTO. What is the result of your CREATE DATABASE statement ?

  1. The oracle server creates no undo tablespace.

  2. The oracle server creates an undo segment in the system tablespace.

  3. The oracle server cerates one undo tablespace with the name SYS_UNDOTBS.

  4. Database creation fails because you did not specify an undo tablespace on the create database statment.


Correct Option: C

John has created a procedure named SALARY_CALC. Which SQL query allow him to view text of procedure?

  1. SELECT text FROM user_source WHERE name = 'SALARY_CALC';

  2. SELECT * FROM user_source WHERE name='SALARY_CALC';

  3. SELECT * FROM user_objects WHERE object_name='SALARY_CALC';

  4. SELECT * FROM user_procedures WHERE object_name='SALARY_CALC';

  5. SELECT text FROM user_source WHERE name='SALARY_CALC' and owner='JOHN'


Correct Option: A
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