NSCT – Advanced SQL MCQs 20 min Score: 0 Attempted: 0/20 Subscribe 1. . A subquery in SQL is: (A) A database (B) A table (C) A query nested inside another query (D) A compressed fileShow All Answers 2. . Correlated subquery differs from a simple subquery because: (A) It compresses tables (B) It does not use outer columns (C) It deletes tables (D) It references columns from the outer query 3. . A self-join is used to: (A) Compress tables (B) Join two different databases (C) Encrypt data (D) Join a table with itself 4. . SQL views are: (A) Encrypted tables (B) Physical copies of tables (C) Compressed tables (D) Virtual tables created by a query 5. . Materialized views differ from regular views because: (A) They compress tables automatically (B) They are virtual only (C) They encrypt data (D) They store actual data for faster access 6. . Indexes in SQL are used to: (A) Improve query performance (B) Encrypt data (C) Delete old records (D) Compress tables 7. . A unique index ensures: (A) Encryption of the table (B) Faster deletion (C) Faster compression (D) No duplicate values in the indexed column(s) 8. . Composite index refers to: (A) Compressed table (B) An index on a single column (C) Encrypted data (D) An index on multiple columns of a table 9. . Transactions in SQL follow: (A) Backup rules only (B) ACID properties – Atomicity, Consistency, Isolation, Durability (C) Compression rules (D) Encryption rules 10. . COMMIT in SQL is used to: (A) Encrypt tables (B) Delete data (C) Compress tables (D) Save all changes made in the current transaction 11. . ROLLBACK in SQL is used to: (A) Compress tables (B) Save changes (C) Encrypt data (D) Undo changes made in the current transaction 12. . SAVEPOINT in SQL allows: (A) Compression of tables (B) Full rollback only (C) Partial rollback within a transaction (D) Encryption of logs 13. . TRIGGER in SQL is: (A) A set of actions automatically executed in response to certain events (B) A compressed table (C) An index (D) A backup file 14. . Stored procedure in SQL is: (A) An index (B) A virtual table (C) A precompiled collection of SQL statements (D) A backup script 15. . Cursor in SQL is used to: (A) Encrypt columns (B) Compress tables (C) Process rows returned by a query one at a time (D) Backup data 16. . Recursive query in SQL is: (A) A query that references itself to retrieve hierarchical data (B) A query that compresses tables (C) A query that encrypts data (D) A query that deletes data 17. . WITH clause (Common Table Expression - CTE) is used to: (A) Encrypt data (B) Delete tables (C) Compress tables (D) Define temporary named result sets for queries 18. . EXISTS operator in SQL is used to: (A) Compress tables (B) Check the existence of rows returned by a subquery (C) Encrypt data (D) Delete data 19. . COALESCE function in SQL returns: (A) The average value (B) The sum of values (C) The first non-NULL value in a list of expressions (D) Number of rows 20. . The main purpose of Advanced SQL features is to: (A) Delete old files (B) Compress data (C) Encrypt tables (D) Efficiently handle complex queries, transactions, and data management tasks
