Computer Science - IT MCQs
Topic Notes: Computer Science - IT
<p>MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.</p>
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
81
What is the primary purpose of creating an Entity-Relationship Diagram (ERD)?
Answer:
All of above
The primary goal of an ERD is to provide a comprehensive visual model of the database. This includes identifying data objects (entities), defining the associations between them, and specifying the cardinality and modality to describe the nature of those relationships.
82
Which of the following components are considered fundamental building blocks in the process of data modeling?
Answer:
All
Data modeling is the process of creating a visual representation of an information system. The core ingredients include entities (the objects being modeled), attributes (the properties of those objects), and relationships (the associations between different entities), all of which are essential for defining a database schema.
83
What is the term for an association created between common fields found in two separate database tables?
Answer:
Relationship
A relationship is a logical connection established between two tables based on common fields, typically linking a primary key in one table to a foreign key in another. This structure is the foundation of relational databases, allowing data to be retrieved from multiple tables simultaneously.
84
What is the primary purpose for subdividing data fields within a database or record structure?
Answer:
always done to give the programmer greater flexibility
Subdividing fields is a fundamental technique in data normalization and database design. By breaking down complex data into smaller, logical components, developers gain increased flexibility in how they manipulate, search, and report on specific pieces of information, which is essential for maintaining efficient and scalable database systems.
85
Which of the following tasks are typically performed during the logical database design phase?
Answer:
All of the above
Logical database design involves mapping the conceptual model into a logical schema. This process includes identifying and representing entities, defining the relationships between them, and applying normalization techniques to ensure data integrity and reduce redundancy within the database structure.
86
During the database development lifecycle, into what is the conceptual data model typically mapped?
Answer:
Implementation model
The database development process involves transitioning from a high-level conceptual model to an implementation model. This model specifies the physical structure and storage details required to deploy the database on a specific database management system.
87
What is the concept of separating the database structure from the application programs that access it called?
Answer:
Data Independence
Data independence is the property of a database system that allows the data structure to be changed without requiring changes to the application programs that access the data. This separation is crucial for maintaining system flexibility and reducing the maintenance burden on software developers.
88
What term describes the techniques used to read and write data to or from storage devices?
Answer:
Access Methods
Access methods are the specific procedures or algorithms used by an operating system or database management system to locate, retrieve, and store data on physical storage media. These methods determine how data is organized and accessed efficiently.
89
What is the formal term for the process of verifying that input data adheres to predefined rules or constraints?
Answer:
Data Validation
Data validation is a critical database process that ensures the accuracy and quality of data by checking input against specific criteria, such as range limits, format requirements, or mandatory fields. This prevents incorrect or inconsistent data from being saved into the database.
90
Which database constraint is specifically designed to ensure that no two rows in a table contain the same value in a particular column?
Answer:
Unique
A Unique constraint ensures that all values in a column are different from one another. While a Primary Key also enforces uniqueness, it additionally requires the column to be non-null. The Unique constraint is specifically used to prevent duplicate entries in columns that are not necessarily the primary identifier for the table records.