Test Bank Database Systems and Database Systems Design, Implementation, & Management, 14th, Exercises of Database Management Systems (DBMS)

Download Test Bank Database Systems and Database Systems Design, Implementation, & Management, 14th and more Exercises Database Management Systems (DBMS) in PDF only on Docsity!

Test Bank

Database Systems

Database Systems Design, Implementation, & Management, 14th Edition Carlos

Corone

🧠 Database Systems Practice Test – Set

1. A database is best defined as:

A. A collection of unrelated files B. A structured collection of data C. A software program D. A web page Answer: B Rationale: A database stores data in an organized way for retrieval.

2. The primary key in a table must be: A. Unique B. Null C. Repeated D. Text only Answer: A Rationale: Primary keys uniquely identify each record. 3. What type of model represents entities and relationships graphically? A. Relational model B. ER model C. Physical model D. Network model Answer: B 4. In SQL, which command is used to retrieve data? A. INSERT B. UPDATE C. SELECT D. DELETE Answer: C 5. Which normal form eliminates partial dependencies?

C. Data modeling D. Normalization Answer: B

10. A foreign key is defined as: A. Unique key B. Primary key in another table C. Index D. Null value Answer: B 11. Which SQL operator is used for partial matches? A. = B. LIKE C. IN D. IS NULL Answer: B 12. Which of the following is a DDL command? A. SELECT B. INSERT C. CREATE D. UPDATE Answer: C 13. A view in SQL is: A. Physical table B. Virtual table C. Stored procedure D. Index

Answer: B

14. The purpose of normalization is to: A. Speed up queries B. Eliminate redundancy C. Create reports D. Store images Answer: B 15. A schema defines: A. Data itself B. Structure of data C. CPU instructions D. Report format Answer: B 16. SQL stands for: A. Simple Query Language B. Structured Query Language C. System Query Level D. Standard Query Logic Answer: B 17. Which constraint ensures uniqueness except primary key? A. CHECK B. UNIQUE C. NOT NULL D. DEFAULT Answer: B

22. Which SQL clause filters aggregated results? A. WHERE B. ORDER BY C. HAVING D. GROUP BY Answer: C 23. A weak entity depends on: A. Itself B. Strong entity C. Foreign key D. Index Answer: B 24. Data independence means the DBMS is separate from: A. Physical storage B. Users C. Reports D. Clients Answer: A 25. Which of the following is NOT a database model? A. Hierarchical B. Relational C. Object-oriented D. Linear Answer: D 26. SQL JOIN that returns only matching rows is:

A. LEFT JOIN

B. RIGHT JOIN

C. INNER JOIN

D. FULL OUTER JOIN

Answer: C

27. A trigger in SQL is: A. Stored table B. Automatic action on event C. User login D. Backup script Answer: B 28. Indexes are used to: A. Store backups B. Speed up data retrieval C. Create tables D. Delete tables Answer: B 29. A many-to-many relationship must be resolved with: A. Normalization B. Intersection (junction) table C. SQL update D. Foreign key only Answer: B 30. Which SQL function returns the number of rows? A. SUM() B. AVG()

A. A table derived from view B. A physical database table C. Temporary table only D. Indexed table Answer: B

35. A surrogate key is: A. Natural key B. Artificial key C. Composite key D. Foreign key Answer: B 36. Which command changes table structure? A. UPDATE B. ALTER C. DROP D. INSERT Answer: B 37. SQL constraint to enforce a condition on column values: A. UNIQUE B. PRIMARY KEY C. CHECK D. FOREIGN KEY Answer: C 38. View advantages include: A. Security B. Simplified queries

C. Data abstraction D. All of the above Answer: D

39. Data definition is done by: A. DDL B. DML C. DCL D. TCL Answer: A 40. A star schema is used in: A. OLTP B. OLAP and data warehousing C. Normalized design D. XML databases Answer: B 41. Entity integrity rule ensures: A. No null primary key B. No foreign key C. No duplicate values anywhere D. No update Answer: A 42. SQL INSERT adds data: A. To database schema B. To tables C. To indexes D. To views only

47. The purpose of data normalization is to: A. Reduce anomalies B. Duplicate data C. Increase storage D. Remove index Answer: A 48. In distributed databases, fragmentation refers to: A. Breaking tables into pieces B. Merging data C. Deleting rows D. Backup only Answer: A 49. A relation in relational databases is: A. Table B. Column only C. Foreign key only D. Stored procedure Answer: A 50. UNION SQL operator does what? A. Combines result sets without duplicates B. Combines and keeps duplicates C. Deletes tables D. Groups data Answer: A

51. SQL SELECT * FROM table WHERE age > 30; returns: A. All rows B. Rows where age > 30 C. Rows where age = 30 D. No rows Answer: B 52. A database transaction should be: A. Partially applied B. All or nothing C. Applied later D. Stored only Answer: B 53. RAID stands for: A. Random Access of Independent Data B. Redundant Array of Independent Disks C. Regular Array of Indexed Data D. Relational Access ID Answer: B 54. A clustered index: A. Sorts data physically B. Creates a copy only C. Has no performance benefit D. Is unnecessary Answer: A 55. Object ‑ oriented databases store:

C. Transactions only D. Keys only Answer: A

60. SQL TRUNCATE TABLE … does: A. Deletes all rows and logs each deletion B. Deletes structure only C. Deletes all rows but cannot be rolled back (DBMS dependent) D. Adds rows Answer: C 🧠 **Database Systems Practice – Set 3 (Q61–90)

1. A stored procedure is:** A. A compiled SQL program B. A backup file C. An index D. A schema Answer: A 62. Deadlock occurs when: A. Two transactions block each other B. Data is deleted C. Backup starts D. Index rebuilds Answer: A 63. SQL VIEW can be used for:

A. Security B. Simplified queries C. Data abstraction D. All of the above Answer: D

64. Distributed database systems improve: A. Data redundancy B. Performance and availability C. No need for backups D. No SQL needed Answer: B 65. SQL GRANT privileges means: A. Remove privileges B. Assign permissions C. Delete privileges D. Backup Answer: B 66. A database trigger can execute when: A. Table is queried B. Data is inserted/updated/deleted C. Backup runs D. Index created Answer: B 67. A recursive relationship means: A. Entity relates to itself B. Two separate entities

Answer: A

72. Database backup types include: A. Full B. Incremental C. Differential D. All of the above Answer: D 73. In an ER diagram, a weak entity is represented by: A. Single rectangle B. Double rectangle C. Diamond D. Circle Answer: B 74. In SQL, DISTINCT keyword is used to: A. Delete duplicates B. Return unique rows C. Group rows D. Sort rows Answer: B 75. In database security, authentication verifies: A. User identity B. Data integrity C. Backup status D. Index performance Answer: A

76. SQL schema can include: A. Tables B. Views C. Indexes D. All of the above Answer: D 77. Replication in databases is used for: A. Data redundancy and availability B. Normalize data C. Delete old data D. Single user access Answer: A 78. A surrogate key is often used because: A. It’s human‑readable B. It’s unique and stable C. It’s always inherited D. It can be null Answer: B 79. SQL HAVING differs from WHERE because: A. WHERE filters groups B. HAVING filters aggregated groups C. HAVING deletes data D. WHERE returns views Answer: B