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

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

  1. Control file

  2. Data file

  3. OnLine ReDo file

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

Data files in Oracle contain the actual user data and system data. Control files contain metadata about the database structure. Redo log files (online and offline) contain transaction records for recovery, not the actual data.

Multiple choice

What is the new Oracle Shared Server?

  1. An improved version of multithreaded server configuration

  2. A connection pooling configuration where several clients are connected to the same server process

  3. Two more database servers, which share data by means of database links; the client software is unaware to which server it is connected

  4. A configuration of Real Application Cluster where the client connection is routed to the least busy instance
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oracle Shared Server is the evolution of the multithreaded server architecture, improving resource utilization through connection pooling and dispatcher processes. Options B and C describe different concepts - B describes basic connection pooling without mentioning dispatcher processes, while C describes Real Application Clusters (RAC). Option D refers to RAC load balancing, not Shared Server.

Multiple choice

The PMON background process performs all system monitoring functions on the oracle database.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

PMON (Process Monitor) performs process monitoring and recovery, but it does NOT perform ALL system monitoring functions. That statement is an overstatement - other background processes like SMON (System Monitor), CKPT (Checkpoint), and archiving processes handle different aspects of system monitoring. PMON specifically monitors failed processes, cleans up their resources, and rolls back their transactions.

Multiple choice

What does unloading of data refer to? How can the ownership of all of a user's objects change during a data pump import?

  1. The reading of data from external datafiles into external tables REMAP_SCHEMA=source_schema:targer_schema

  2. The writing of data from Oracle tables to external datafiles REMAP_TABLESPACE=source_tablespace:target_tablespace

  3. The writing of data from external datafiles into external tables FROMUSER TOUSER

  4. The reading of data from Oracle tables into external datafilesREMAP_TABLESPACE=source_tablespace:source_tablespace
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice

Which table type should be used to provide fast key-based access to table data for queries involving exact matches and range searches?

  1. Regular table

  2. Clustered table

  3. Partitioned table

  4. Index-organized table
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Index-organized tables (IOTs) store rows in B-tree index structure sorted by primary key, providing fast key-based access for both exact matches and range searches. Regular tables store rows in heap format, clustered tables group related tables together physically, and partitioned tables divide data into segments but don't optimize key-based access specifically.

Multiple choice

What is the equivalent of the old DROP TABLE command in Oracle Database 10g?

  1. DROP TABLE NO PURGE

  2. DROP TABLE works exactly the way it did in previous versions.

  3. DROP TABLE … PURGE

  4. DROP TABLE … TO BEFORE DROP
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Oracle 10g, DROP TABLE by default moves tables to the recyclebin. The PURGE option drops the table permanently without sending it to the recyclebin, making it equivalent to pre-10g DROP TABLE behavior. DROP TABLE NO PURGE is not valid syntax, and DROP TABLE...TO BEFORE DROP is used for flashback recovery, not permanent deletion.

Multiple choice

Which Oracle Net Services feature supports authentication methods such as token cards through the use of authentication adapters?

  1. Heterogeneous Services

  2. Firewalls

  3. Oracle Advanced Security

  4. Oracle Connection Manager
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oracle Advanced Security Option provides authentication adapters that support various methods including token cards, biometrics, and Kerberos. Heterogeneous Services is for non-Oracle data access, Firewalls are network security devices, and Oracle Connection Manager handles connection pooling and multiplexing but not advanced authentication.

Multiple choice

Which of the following statements about an Oracle instance is true?

  1. The redo log buffer is NOT a part of the shared memory area of an Oracle instance.

  2. Multiple instances can be executed on the same computer, each accessing its own physical database.

  3. An Oracle instance is a combination of memory structures, background processes, and user processes.

  4. In a shared server environment, the memory structure component of an instance consists of a single SGA and a single PGA.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiple Oracle instances can run on the same machine, each accessing separate physical databases - this is how Oracle Real Application Clusters (RAC) and standalone instances coexist. Option A is incorrect because redo log buffer IS part of SGA. Option C is incorrect because instances consist of memory structures and background processes, not user processes. Option D is incorrect because shared server environments have one SGA but multiple PGAs (one per server process).