T4Tutorials .PK

NSCT – Advanced SQL MCQs

1. . A subquery in SQL is:

(A) A database


(B) A table


(C) A query nested inside another query


(D) A compressed file




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




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