ICT - Information Communication Technology Database Management Concepts Questions and Answers — Questions and Answers
Question 1: A database administrator is designing a relational database and wants to minimize data redundancy and prevent update anomalies. The process of organizing columns and tables to achieve this is known as:
- Indexing
- Normalization (Correct answer)
- Query Optimization
- Transaction Management
Correct answer: Normalization
Normalization is the process of structuring a relational database to reduce data redundancy and improve data integrity. [10, 2] It involves dividing larger tables into smaller, well-structured tables and defining relationships between them. [1] Indexing improves retrieval speed, query optimization enhances query performance, and transaction management ensures data consistency during transactions.
Question 2: In a relational database, which of the following is used to uniquely identify each record in a table and establish a link to data in another table?
- Foreign Key
- Composite Key
- Super Key
- Primary Key (Correct answer)
Correct answer: Primary Key
A Primary Key is a constraint that uniquely identifies each record in a database table. [26] To link this table with another, the primary key of the first table is referenced in the second table, where it is known as a Foreign Key. [9, 31] While other keys exist, the Primary Key serves the fundamental role of unique identification within its own table.
Question 3: A financial application requires that database transactions are processed reliably. If a multi-step transaction fails midway, all changes made up to that point must be undone to prevent data inconsistency. Which ACID property ensures this 'all-or-nothing' behavior?
- Isolation
- Durability
- Atomicity (Correct answer)
- Consistency
Correct answer: Atomicity
Atomicity is the ACID property that guarantees transactions are treated as a single, indivisible unit. [27] This means the entire transaction either completes successfully, or if any part of it fails, the entire transaction is rolled back, leaving the database in its original state. [27, 12] This prevents partial updates and ensures data integrity.
Question 4: A developer needs to add a new table to an existing database schema. Which subset of SQL (Structured Query Language) commands would they use to accomplish this task?
- Data Manipulation Language (DML)
- Data Control Language (DCL)
- Transaction Control Language (TCL)
- Data Definition Language (DDL) (Correct answer)
Correct answer: Data Definition Language (DDL)
Data Definition Language (DDL) is the subset of SQL used to define and manage the structure of database objects. [14, 11] The `CREATE TABLE` command, used to add a new table, is a core DDL command, along with `ALTER` and `DROP`. [6, 11] DML is used for manipulating data (INSERT, UPDATE), DCL for permissions (GRANT, REVOKE), and TCL for transaction management (COMMIT, ROLLBACK).
Question 5: A company is developing a new social media platform that needs to handle massive amounts of unstructured data, such as user posts, images, and videos. The priority is high availability and horizontal scalability. Which type of database model would be MOST suitable for this scenario?
- Relational (SQL)
- Hierarchical
- NoSQL (Correct answer)
- Object-Oriented
Correct answer: NoSQL
NoSQL databases are specifically designed for large volumes of unstructured or semi-structured data and prioritize scalability and availability. [8, 19] They use flexible data models (like document, key-value, or graph) which are better suited for the diverse data types of a social media platform than the rigid, table-based structure of relational (SQL) databases. [4, 13]
Question 6: To improve the performance of data retrieval operations, a database administrator creates a special lookup table that the database search engine can use to speed up queries. This data structure maps column values to the physical location of the corresponding data rows. What is this structure called?
- View
- Trigger
- Index (Correct answer)
- Stored Procedure
Correct answer: Index
A database index is a data structure that improves the speed of data retrieval operations on a table. [5, 25] It works like the index of a book, allowing the database to find the location of specific data quickly without having to scan the entire table. [7, 30] A View is a virtual table, a Trigger is an automated procedure, and a Stored Procedure is a pre-compiled set of SQL statements.
ICT - Information Communication Technology Database Management Concepts Questions and Answers
A database administrator is designing a relational database and wants to minimize data redundancy and prevent update anomalies.
The process of organizing columns and tables to achieve this is known as: