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

In which of the following degrees of durability, if only the primary is active, the transaction is allowed to commit as soon as its commit log record is written to stable storage at the primary site?

  1. One-safe

  2. Detection of failure

  3. Proxy achived log backups

  4. Media management application

  5. Two-safe
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

If only the primary is active, the transaction is allowed to commit as soon as its commit log record is written to stable storage at the primary site.

Multiple choice

The problem with which of the following classifications of degree of durability is that transaction processing cannot proceed, if either the primary or the backup site is down?

  1. One-safe

  2. Two-very-safe

  3. Detection of failure

  4. Proxy archived log backups

  5. Media management application
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The problem with this classification of degree of durability is that transaction processing can not proceed if either the primary or the backup site is down.

Multiple choice

On enabling which of the following features does the database automatically create, delete and manage flashback logs inside the flash recovery area?

  1. Recovery through resetlogs

  2. Proxy archived log backups

  3. Oracle flashback database

  4. Duplicate database

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

When you enable the flashback database feature, the database automatically creates, deletes and manages flashback logs inside the flash recovery area.

Multiple choice

Which one of the following is a Data Base Management System?

  1. MS Access

  2. MS Excel

  3. MS Outlook

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

MS Access is a relational database management system designed specifically for creating and managing databases. MS Excel is a spreadsheet application, MS Outlook is an email client, and neither are database management systems.

Multiple choice

Which of the following is true about the SQL Tuning Advisor?

  1. It automatically collects statistics if they are missing

  2. It only makes recommendations to collect statistics

  3. It ignores optimizer statistics completely

  4. It uses only the available statistics
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The SQL Tuning Advisor is an Oracle tool that analyzes SQL statements and provides recommendations for performance improvement, including automatically collecting missing optimizer statistics when needed. While it can recommend statistics collection (option B), it can also proactively collect them. Option C is incorrect because the advisor heavily relies on optimizer statistics for analysis. Option D is incomplete because the advisor will collect missing statistics rather than work with incomplete data.

Multiple choice

MARY wants to create an image copy backup that can be used in an incremental backup set. She wants to allocate the C1 channel and create image copies of two data files. She does NOT want the Oracle Server session to perform logical block corruption detection. These image copies will be used in an incremental backup set. Which RUN block set of commands should she use?

  1. rman> RUN 2> CHECK LOGICAL 3> ALLOCATE CHANNEL c1 TYPE DISK; 4> DATAFILE 1 TO '/backup/f1.dbf', 5> DATAFILE 2 TO '/backup/f2.dbf';

  2. rman> RUN 2> ALLOCATE CHANNEL c1 TYPE DISK; 3> COPY LEVEL 0 4> DATAFILE 1 TO '/backup/f1.dbf', 5> DATAFILE 2 TO '/backup/f2.dbf';

  3. rman> RUN 2> ALLOCATE CHANNEL c1 TYPE DISK; 3> DATAFILE 1 TO '/backup/f1.dbf', 4> DATAFILE 2 TO '/backup/f2.dbf';

  4. rman> RUN 2> ALLOCATE CHANNEL c1 TYPE sbt_tape; 3> DATAFILE 1 TO '/backup/f1.dbf', 4> DATAFILE 2 TO '/backup/f2.dbf';
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Option B is correct because it specifies COPY LEVEL 0 to create a level 0 image copy suitable for incremental backups, allocates a DISK channel (c1), and omits CHECK LOGICAL as requested. Option A includes CHECK LOGICAL, which performs logical block corruption detection - exactly what Mary wants to avoid. Option C is missing the LEVEL 0 specification required for incremental backup compatibility. Option D allocates an sbt_tape channel instead of the required DISK channel.

Multiple choice

Which system privilege must the RMAN user have to be able to connect and execute RMAN commands on a target database?

  1. SYSDBA

  2. SYSOPER

  3. No system privileges are required for the RMAN user

  4. Only SYS user can connect and execute RMAN commands on a target database
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

RMAN (Recovery Manager) requires the SYSDBA privilege to connect to a target database and perform backup and recovery operations. This is because RMAN needs to read and write critical database files, including data files, control files, and redo logs - operations that demand database administrator level privileges. SYSOPER (option B) provides more limited privileges. Option C is incorrect - privileges are mandatory. Option D is false because users other than SYS can connect if granted SYSDBA.

Multiple choice

What Oracle backup and recover file contains user and system data?

  1. Control file

  2. Datafile

  3. OnLine ReDo file

  4. Offline ReDo file
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Datafiles are the Oracle files that contain actual user data and system data stored in tables, indexes, and other database segments. Control files (option A) contain metadata about the database structure but not the actual data. Online and offline redo log files (options C and D) contain transaction records for recovery purposes, not user or system data themselves. When users insert, update, or query data, they are interacting with data stored in datafiles.