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
51
A set of programs that handle a firm's database responsibilities is called:
Answer:
A. Database management system (DBMS)
While Database Management System (DBMS) is the most common and standard term, other terms like Data Management System (DMS) and Database Processing System (DBPS) are also used to describe the collection of software that manages a database.
52
Which of the following contains a complete record of all activity that affected the contents of a database during a certain period of time?
Answer:
Transaction log
A transaction log is a special file that sequentially records all transactions and modifications made to a database. This log is essential for database recovery and for maintaining the integrity of the data.
53
Which data model was the first to be developed?
Answer:
Hierarchical model
The hierarchical model is one of the oldest data models, developed in the 1960s by IBM. It was used in early mainframe database management systems like IMS (Information Management System).
54
The `ON UPDATE SET NULL` clause in a foreign key constraint means:
Answer:
The update operation on the parent table is blocked.
This referential action specifies that if the referenced primary key in the parent table is updated, the values of the matching foreign key in the child table should be set to NULL. This requires the foreign key column to be nullable.
55
Denormalization typically represents a trade-off between increasing data redundancy and improving:
Answer:
Read performance
The main reason to denormalize a database is to improve query (read) performance. By adding redundant data, you can reduce the number of expensive table joins needed to retrieve data, making queries faster.
56
What does the 'C' in the ACID properties of a transaction stand for?
Answer:
Consistency
Consistency ensures that a transaction brings the database from one valid state to another. Any data written to the database must be valid according to all defined rules, including constraints, cascades, and triggers.
57
What is one approach to standardizing the storage of data?
Answer:
CODASYL specification
The CODASYL (Conference on Data Systems Languages) specification was an influential early effort to create standards for database definition and structure, particularly for the network data model.
58
The relational model stores data in:
Answer:
Two-dimensional tables
The fundamental structure of the relational data model is the table (or relation), which is a two-dimensional grid consisting of rows (tuples) and columns (attributes).
59
What is the name given to the database management system which is able to handle full text data, image data, audio, and video?
Answer:
Multimedia
A multimedia DBMS is specifically designed to store, manage, and retrieve diverse and complex data types beyond traditional text and numbers, including images, audio files, and video clips.
60
One data dictionary software package is called:
Answer:
DB/DC dictionary
A DB/DC (Database/Data Communications) dictionary is a specific type of software tool used as a central repository for metadata, which is information about the data definitions, structures, and relationships within a database.