Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
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
291
Denormalization is most beneficial in which type of system?
Answer:
Read-heavy systems like data warehouses
Denormalization is a technique used to optimize the read performance of a database. It is most suitable for systems where data is read far more frequently than it is written, such as in data warehousing and business intelligence applications.
292
The main purpose of a primary key in a database is to:
Answer:
Uniquely identify a record
The primary key ensures that each record in a table is distinct and can be uniquely identified.
293
Accessing data by navigating through a series of pointers or links from one record to another is a characteristic of which data models?
Answer:
Hierarchical and Network Models
Both the hierarchical and network models are considered navigational databases. To retrieve data, an application program must traverse a path through the data structure using predefined links or pointers.
294
What does the acronym DBMS stand for?
Answer:
Database Management System
DBMS stands for Database Management System. It is the software that interacts with end-users, applications, and the database itself to capture and analyze the data.
295
To sort the results of a query in descending order, which keyword should be used with `ORDER BY`?
Answer:
DESC
The `DESC` keyword is used with the `ORDER BY` clause to sort the data in descending order (from highest to lowest). The default sorting order is ascending (`ASC`).
296
Data becomes __ when presented in a way people can understand and use.
Answer:
Information
Data is raw facts, while information is data that has been processed into a meaningful and useful context.
297
Under which circumstances is a batch processing system typically the most suitable approach for data handling?
Answer:
When there is a high volume of similar data inputs that can be efficiently processed together at scheduled intervals.
Batch processing is most appropriate for scenarios involving a large volume of data that can be collected over time and processed together as a single block or 'batch.' This method is efficient when immediate, real-time processing is not critical and data can be accumulated. Examples include payroll processing, utility billing, or end-of-day financial settlements. Option (a) describes real-time processing. Option (c) also points towards real-time or interactive processing where delays are unacceptable. Option (d) is partially true for batch processing, as it can optimize overall resource use by scheduling large jobs, but the core suitability lies in the volume and non-immediacy of transactions, not solely minimizing per-transaction resource use, and it is not its primary goal. Therefore, a high volume of similar data processed together at intervals (option b) is the defining characteristic for batch processing suitability.
298
What is the main purpose of normalization?
Answer:
To minimize data redundancy
Normalization is the process of structuring a relational database to minimize data redundancy and dependency. This improves data integrity and reduces the risk of data anomalies (insertion, update, and deletion anomalies).
299
In the context of the relational model, a 'schema' refers to the:
Answer:
Design or blueprint of the database structure, including tables and their columns.
The database schema is the formal description of the database's structure. It defines the relations (tables), their attributes (columns), data types, relationships, and constraints.
300
A 'determinant' in a functional dependency (X → Y) is:
Answer:
The attribute that determines the other (X).
In the functional dependency X → Y, the attribute or set of attributes on the left side (X) is called the determinant, as its value determines the value of the attribute(s) on the right side (Y).