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
241
Which is not true for the traditional information processing approach?
Answer:
There is common sharing of data among the various applications
Traditional information processing systems were file-oriented and created data silos, where each application had its own separate files. This made common data sharing between different applications very difficult, unlike the integrated approach of a DBMS.
242
A command that lets you change one or more fields in a record is:
Answer:
Modify
The modify command, known as `UPDATE` in standard SQL, is the specific DML command used to alter or change the data within one or more existing records in a table.
243
When you link one database table to another, what are you creating?
Answer:
Relationships
Linking tables via keys like primary and foreign keys establishes relationships, which allows data to be efficiently combined and retrieved across multiple tables.
244
A telephone number, birth date, and customer name are examples of:
Answer:
Record
A record is a collection of related fields of data treated as a single unit, such as all the information about one customer.
245
The view level of abstraction is primarily concerned with:
Answer:
Hiding parts of the database from certain users.
The view level is the highest level of abstraction. It describes only a part of the entire database relevant to a particular user or group of users. This simplifies interaction and enhances security by hiding sensitive or irrelevant data.
246
Which TCL command is used to create a point in a transaction to which you can later roll back?
Answer:
SAVEPOINT
The `SAVEPOINT` command is used to temporarily save a transaction so that you can roll back to that point whenever necessary. It allows you to undo parts of a transaction instead of the entire transaction.
247
What does the `DROP TABLE` command do?
Answer:
It permanently deletes the table structure, its data, and all related objects like indexes.
`DROP TABLE` is a DDL command that completely removes a table from the database. This operation is irreversible and deletes the table's definition, all its data, and associated indexes and constraints.
248
Microsoft Access and MySQL are examples of __.
Answer:
Database management systems (DBMSs)
Both are popular DBMS software used to create, manage, and interact with databases.
249
What are the rules that restrict how data is entered into a database?
Answer:
Constraints
Constraints are rules enforced on data columns in a table to ensure the accuracy and reliability of the data.
250
What does a dashed underline for an attribute in an ER diagram signify?
Answer:
It is a partial key (discriminator).
The partial key, or discriminator, of a weak entity is underlined with a dashed line. This attribute helps distinguish instances of the weak entity in relation to its owner entity.