NCST – Relational Database Concepts MCQs 20 min Score: 0 Attempted: 0/20 Subscribe 1. . A relational database stores data in: (A) Tree structures only (B) Tables consisting of rows and columns (C) Graph structures only (D) Files without structureShow All Answers 2. . In relational databases, a tuple refers to: (A) A database schema (B) A column in a table (C) A foreign key (D) A single row in a table 3. . A relation in a relational database is: (A) A table with rows and columns (B) A backup file (C) A compressed table (D) An encrypted file 4. . Primary key in a table: (A) Encrypts data automatically (B) Uniquely identifies each row (C) Compresses the table (D) Deletes old records 5. . Foreign key is used to: (A) Compress files (B) Encrypt data (C) Establish a link between two tables (D) Delete logs 6. . Candidate key refers to: (A) Only the primary key (B) Any attribute or set of attributes that can uniquely identify a tuple (C) Encrypted attributes (D) Compressed columns 7. . Super key is: (A) A set of one or more attributes that uniquely identify a tuple (B) A compressed key (C) An encrypted key (D) A backup key 8. . Alternate key is: (A) A foreign key (B) A candidate key not chosen as the primary key (C) An encrypted key (D) Compressed column 9. . Composite key is: (A) A compressed key (B) A backup key (C) A foreign key (D) A key formed from two or more attributes to uniquely identify a tuple 10. . Domain in relational databases refers to: (A) A table name (B) The set of valid values an attribute can have (C) A compressed column (D) An encrypted key 11. . Referential integrity ensures: (A) Data is encrypted (B) Tables are compressed (C) Foreign key values must match primary key values in the referenced table (D) Backups are consistent 12. . Entity integrity ensures: (A) All tables are compressed (B) Foreign key values are unique (C) Primary key values cannot be NULL (D) Data is encrypted 13. . Relational algebra is used to: (A) Delete old records (B) Compress tables (C) Encrypt data (D) Perform queries and operations on relational databases 14. . Relational calculus is: (A) A backup procedure (B) A table compression method (C) A non-procedural query language based on mathematical predicate calculus (D) Encryption algorithm 15. . A view in relational databases is: (A) Compressed file (B) A physical backup (C) An encrypted table (D) A virtual table derived from a query 16. . Normalization in relational databases is used to: (A) Compress files (B) Reduce redundancy and improve data integrity (C) Encrypt data (D) Delete old records 17. . Denormalization is done to: (A) Compress tables (B) Encrypt tables (C) Improve query performance by reducing joins (D) Delete redundant rows 18. . Tuple relational calculus is: (A) Backup procedure (B) A compression method (C) An encryption algorithm (D) A declarative language where queries describe what to retrieve, not how 19. . Attribute in a relational table refers to: (A) A row (B) A column representing a property of an entity (C) A table (D) A database schema 20. . The main purpose of relational database concepts is to: (A) Delete old records (B) Compress files (C) Encrypt tables (D) Organize data efficiently, maintain integrity, and support queries
