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

These are five records in a data base:

     
Name Age Occupation Category
Neha 23 CON A
Dhruti 24 ENG B
Sonika 25 DOC C
Poonam 26 SER D

There is an index file associated with this and it contains the values: 1, 3, 2, 4. Which of the following fields is the index built form?

  1. Age

  2. Name

  3. Occupation

  4. Category

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

Sorting records by Occupation alphabetically: CON(1), DOC(3), ENG(2), SER(4) gives the index order [1,3,2,4]. This matches the given index file values.

Multiple choice

What is the structure of a data base called?

  1. Data Dictionary

  2. Schema

  3. Table

  4. DBMS

  5. Database Abstraction Layer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Schema is the structure of a database system, described in a formal language supported by the database management system (DBMS). In a relational database, the schema defines the tables, the fields in each table, and the relationships between fields and tables.

Multiple choice

Which of these techniques used in database transactions is also called UNDO/REDO technique?

  1. Deferred update

  2. Immediate update

  3. Rollback

  4. Commit

  5. Phantom reads
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Immediate update also called UNDO/REDO, is also another technique used to recover/support transaction failures that occur due to operating system, power, memory or machine failures. When a transaction runs, any of the updates or alterations made by the transaction are written directly in to the database.

Multiple choice

Which of these properties do not characterize a data warehouse?

  1. Subject Oriented

  2. Integrated

  3. Nonvolatile

  4. Time Invariant

  5. Ad hoc queries
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In order to discover trends in business, analysts need large amounts of data. A data warehouse is time variant. A data warehouse's focus on change over time is what is meant by the term time variant.