Tag: databases

Questions Related to databases

You work as a database administrator for TCS .com. In your production database, the size of Database Buffer Cache needs to be increased immediately for the current as well as future instances of the database. The Oracle instance has been configured to accommodate any changes in the size of the memory structures. At this is production database, you want to accomplish this task with no impact on the user's connections. Which activity must you have completed before accomplishing this task?
technology databases

  1. You must have started the database instance in restricted mode.

  2. You must have started the database instance in NORMALmode.

  3. You must have started the database instance with server parameter file.

  4. You must have started the database instance but must not have mounted.

  5. You must have started the database instance but must not have opened.

Show answer
Correct Option: C

Your TCS .com database is in ARCHIVELOG mode. The data file that belongs to the SYSTEMtablespacehas become corrupted. Up to what point can you recover the database?
technology databases

  1. Until last commit

  2. Until the time you perform recovery

  3. Until the time the date file got corrupted

  4. Until the point where the last transaction begun

  5. You cannot recover the SYSTEM tablespaceand must re-create the database.

Show answer
Correct Option: A

You work as a database administrator for TCS .com. The UNDO_RETENTION parameter in your database is set to 1000 and undoretention is not guaranteed. Which statement regarding retention of undo data is correct?

technology databases

  1. Undo data becomes obsolete after 1,000 seconds.

  2. Undo data gets refreshed after 1,000 seconds.

  3. Undo data will be stored permanently after 1,000 seconds.

  4. Committed undo data would be retained for 1,000 seconds if free undo space is available.

  5. Undo data will be retained in the UNDOtablespacefor 1,000 seconds, then it gets movedmovedto the TEMPORARY tablespace to provide read consistency.

Show answer
Correct Option: D

AI Explanation

To answer this question, we need to understand the concept of the UNDO_RETENTION parameter and its effect on the retention of undo data in a database.

The UNDO_RETENTION parameter is used to specify the minimum amount of time (in seconds) that Oracle should attempt to retain undo data before it is overwritten. It does not guarantee the retention of undo data for the specified duration; rather, it provides a target for Oracle to aim for.

Option A) Undo data becomes obsolete after 1,000 seconds. This option is incorrect. The UNDO_RETENTION parameter does not make the undo data obsolete after a specific duration. It only sets a target retention time.

Option B) Undo data gets refreshed after 1,000 seconds. This option is incorrect. The UNDO_RETENTION parameter does not refresh the undo data after a specific duration. It only sets a target retention time.

Option C) Undo data will be stored permanently after 1,000 seconds. This option is incorrect. The UNDO_RETENTION parameter does not store undo data permanently. It only sets a target retention time.

Option D) Committed undo data would be retained for 1,000 seconds if free undo space is available. This option is correct. When the UNDO_RETENTION parameter is set, committed undo data will be retained for the specified duration if there is enough free undo space available. If free undo space is not available, then the oldest undo data may be overwritten.

Option E) Undo data will be retained in the UNDO tablespace for 1,000 seconds, then it gets moved to the TEMPORARY tablespace to provide read consistency. This option is incorrect. The UNDO_RETENTION parameter does not involve moving undo data to the TEMPORARY tablespace. The UNDO tablespace is specifically used to store undo data.

Therefore, the correct answer is Option D. Committed undo data would be retained for 1,000 seconds if free undo space is available.

You work as a database administrator for TCS .com. On a Monday morning, you find the database instance aborted. After inspecting the alert log file, you execute the STARTUP command in SQL*Plus to bring the instance up. What statement is true?
technology databases

  1. PMON coordinates media recovery.

  2. SMON coordinates instance recovery.

  3. PMON coordinates instance recovery.

  4. Undo Advisor would roll back all uncommitted transactions.

  5. SQL*PLUS reports an error with the message asking you to perform instance recovery.

Show answer
Correct Option: B

You work as a database administrator for TCS .com. The database is open. A media failure has occurred, resulting in loss of all the control files in your database. Which statement regarding the database instance is true in this scenario?
technology databases

  1. The instance would hang.

  2. The instance needs to be shut down.

  3. The instance would be in the open state.

  4. The instance would abort in such cases.

  5. The instance would be in the open and invalid state.

  6. The instance would in the open state, but all the background processes will be restarted.

Show answer
Correct Option: D

You are working on the TCS database. What is the default name of the alert log file in this database?

technology databases

  1. alert_TCS.log

  2. alertlog_TCS.log

  3. TCS _alert_log.log

  4. log_alert_TCS.log

  5. trace_alert_TCS.log

Show answer
Correct Option: A

In your DB -multiplexed online redo log files,one of the members in a group is lost due to media failure? You wud..
technology databases

  1. import the database from the last export

  2. restore all the members in the group from the last backup

  3. drop the lost member from the database and then add a new member to the group

  4. restore all the database files from the backup and then perform a complete recovery

  5. restore all the database files from the backup and then perform an incomplete recovery

Show answer
Correct Option: C

Which statement regarding an incomplete recovery is true?(Oracle 10g)
technology databases

  1. You do not need to restore all the data files.

  2. You do not need to open the database with the RESETLOGS operation

  3. You do not need to perform a full backup after the RESETLOGS operation.

  4. You do not need to recover all the data files to the same system change number (SCN).

Show answer
Correct Option: C

In which scenarios would you rebuild an index?
technology databases

  1. when you need to disable the index usage

  2. when you need to move the index to another tablespace

  3. when you need to enable index monitoring

  4. none of the above

Show answer
Correct Option: B

A redo log file is corrupted while the database is open;You would ..
technology databases

  1. clear the redo log group

  2. perform redo log file import

  3. perform an incomplete recovery

  4. perform a redo log recovery using Recovery Manager (RMAN)

  5. shut down the database and open the database in the NOARCHIVELOGmode

Show answer
Correct Option: A