Computer Knowledge

Database Management Systems

5,543 Questions

Database Management Systems (DBMS) form the core framework for data storage, retrieval, and security in modern software applications. Concepts such as the E-R model, backup planning, SQL integration, and big data architecture are essential for computer knowledge sections. This hub offers a comprehensive set of practice questions to master DBMS fundamentals and advanced database operations.

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Database Management Systems Questions

Multiple choice technology databases

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.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

CONFIGURE RETENTION POLICY CLEAR resets the retention policy to its default setting, which is REDUNDANCY 1. This means RMAN will retain one backup of each file and consider older backups of the same file as obsolete.

Multiple choice technology databases

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
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When starting the listener using the command 'START' without specifying a name, the Listener Control utility defaults to starting the listener named 'LISTENER'.

Multiple choice technology databases

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
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

SMON (System Monitor) performs instance recovery when an Oracle instance restarts after a failure. In a nondistributed configuration, SMON rolls forward changes in the online redo log and rolls back uncommitted transactions to bring the database to a consistent state.

Multiple choice technology databases

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.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oracle supports online index rebuild using ALTER INDEX ... REBUILD ONLINE, which allows the index to be rebuilt while users continue to access the table. You don't need to drop and recreate the index. While fragmentation resolution does depend on index type, the key capability for 24/7 systems is online rebuild.

Multiple choice technology databases

SQL> CREATE TABLESPACE user_data EXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO; Which twp assumptions must be true for this statement to execute successfully ? (Choose two)

  1. Oracle Managed Files used for this instance.
  2. The USER_DATA tablespace in managed using FET$/UET$ tables.

  3. The COMPATIBLE intialization paramter must be 9.0.0 or higer.

  4. Space within segments is the USER_DATA tablespace is managed with freelists.
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice technology databases

Which three attributes of the LOG_ARCHIVE_DEST_n initialization parameter control the data availability mode of a Data Guard standby database? (Choose three)

  1. SYNC or ASYNC to identify the network transmission mode.

  2. LGWR or ARCH to identify the primary database process responsible for sending redo information to the standby.

  3. AFFIRM or NOAFFIRM to control whether log archiving disk write operations are to be performed synchronously or asynchronously.

  4. PROTECTED or UNPROTECTED to control the degree of divergence and data loss at the standby database.
Reveal answer Fill a bubble to check yourself
A Correct answer