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

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
Multiple choice technology databases

What file will give you Oracle instance status information?

  1. alert.ora

  2. init.ora

  3. tnsname.ora

  4. redolog
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The alert log file (alert.log or alert_.log) is the primary source for Oracle instance status information. It contains database startup/shutdown messages, error messages, checkpoint information, and critical events. The init.ora file contains initialization parameters, tnsnames.ora holds network connection details, and redo log files store transaction records - none provide instance status.

Multiple choice technology enterprise content management

An item in a taxonomy (Hierarchical navigation of content by category)

  1. Ontology

  2. Facet

  3. Dictionary

  4. intent
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A facet represents an attribute or category in a faceted classification system, which allows users to navigate content hierarchically by selecting different criteria. Ontologies define complex relationships between concepts, dictionaries store word definitions, and intents represent user goals in natural language processing, making them incorrect in this context.

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

The System Monitor (SMON) background process is responsible for performing instance recovery when a crashed database is reopened. It applies redo log entries (roll forward) and discards uncommitted changes (roll back). PMON cleans up failed user processes, RECO resolves distributed transactions, and CKPT updates file headers during checkpoints.

Multiple choice technology databases

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

In a locally managed tablespace with UNIFORM SIZE specification, all extents are allocated at the uniform size specified (1 MB in this case). The extent is the basic unit of allocation - not segments, Oracle blocks, or OS blocks. Each extent will be exactly 1 MB regardless of the segment size or Oracle block size. This simplifies space management and reduces fragmentation.

Multiple choice technology databases

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

A checkpoint records the highest SCN written to data files. During recovery, only redo records with SCNs higher than the checkpoint SCN need to be applied - changes below that point are already persisted. This dramatically reduces recovery time. Option A is wrong because checkpoint doesn't define SCN, B is wrong because redo above checkpoint is NOT written to data files yet, and D refers to a different parameter.

Multiple choice technology databases

What should you look at to compute the number of undo blocks written per second on disk ?
  1. V$UNDOSTAT
  2. V$TRANSACTION
  3. V$ROLLSTAT

  4. DBA_UNDO_EXTENTS

  5. DBA_ROLLBACK_SEGS
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The V$UNDOSTAT dynamic performance view contains statistics for monitoring the effects of undo space management, including the number of undo blocks consumed (UNDOBLKS) in 10-minute intervals. This data allows administrators to calculate the rate of undo blocks written per second. Other views do not provide this specific time-series undo block data.

Multiple choice technology databases

In user-managed backup and recover procedure, how are data files backed up ?

  1. Using SQL commands.

  2. Using SQL*Plus Commands.

  3. Using operating system commands.

  4. Using Recover Manager commands.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In user-managed backups, the database administrator manually copies the database files using operating system copy utilities (such as cp or copy) after putting the tablespaces into backup mode. SQL or SQL*Plus commands are used to manage the database state, but they do not perform the actual file copying.

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

The CONFIGURE ... CLEAR command in RMAN resets the specified configuration parameter back to its default value. For the retention policy, the default setting is REDUNDANCY 1. It does not remove the retention policy entirely, nor does it cause the DELETE OBSOLETE command to fail.

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

Running the START command in the LSNRCTL utility without specifying a listener name starts the default listener, which is named LISTENER. TNSLSNR is the executable program name, not the listener name, while LOCAL_LISTENER is an initialization parameter, and DEFAULT_LSRN is not a standard default name.