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Aptitude · Reasoning · English · CS — Corporate & Campus Interview Prep
Showing 91–94 of 94 questions
Q.91
Easy
Database/SQL
In SQL, what does the GROUP BY clause do?
Correct Answer:
B. Aggregates rows into groups based on specified columns
Explanation:
GROUP BY groups rows with identical values in specified columns, used with aggregate functions like COUNT(), SUM().
Q.92
Easy
Database/SQL
In a relational database, which normal form eliminates partial dependencies and is considered essential for most practical database designs?
Correct Answer:
B. Third Normal Form (3NF)
Explanation:
3NF eliminates partial and transitive dependencies, making it the standard for practical database design. BCNF is stricter but 3NF is the most commonly implemented normalization form.
Q.93
Easy
Database/SQL
Which of the following is a characteristic of NoSQL databases that makes them suitable for handling big data in cloud environments?
Correct Answer:
B. Horizontal scalability and schema-less design
Explanation:
NoSQL databases like MongoDB and Cassandra are designed for horizontal scaling and flexible schemas, making them ideal for cloud-based big data applications with varying data structures.
Q.94
Easy
Database/SQL
Which of the following represents a vulnerability in SQL query construction that can be exploited through malicious user input, and can be prevented using parameterized queries?
Correct Answer:
C. SQL injection attacks
Explanation:
SQL injection occurs when untrusted input is concatenated into SQL queries. Parameterized queries/prepared statements separate code from data, preventing attackers from modifying query logic.