Chapter 6 AIS

9. If a vendor can supply many items, and if an item can be supplied by only one vendor, then the relationship going from VENDORS to ITEMS is: a. 1:M b. M:1 c. M:M d. a and b e. none of the above

a. 1:M

18. In a table, a foreign key can be either ___________ or ___________. a. a non-key attribute, part of a composite primary key b. a primary key, a non-key attribute c. single valued, multi-valued d. a primary key, a candidate key e. a duplicate key, a unique key

a. a non-key attribute, part of a composite primary key

4. The language used to create the database schema is the a. data definition language b. data manipulation language c. data query language d. all of the above e. a and b

a. data definition language

2. A _________ key is a non-key attribute in a data set which is the primary key in another data set. a. foreign b. concatenated c. composite d. candidate e. non-unique

a. foreign

15. Entries to table fields can be restricted using a. validation rules b. text field format c. digital certificates d. queries e. views

a. validation rules

3. In database terminology, another term for a view is a. virtual table b. form c. screenshot d. data set e. QBE

a. virtual table

16. SQL and QBE are examples of a. DDL -- data definition language b. DQL -- data query language c. DML -- data manipulation language d. 3GL -- third generation language e. OOPL -- object-oriented programming language

b. DQL -- data query language

7. In the database approach, the functions of data backup, control, and security a. cannot be performed. b. are centralized. c. must be programmed into each application. d. are not important. e. cause data redundancy.

b. are centralized.

14. The term "data independence" means that a. data structures and procedures are defined within the same program. b. data structures and procedures are defined separately, allowing each to be modified independent of the other. c. data items are stored independently with minimal data redundancy. d. data structures and files are stored independently. e. data structures and files are stored together but independent of programs.

b. data structures and procedures are defined separately, allowing each to be modified independent of the other.

5. The term "legacy systems" refers primarily to a. database systems accessible with a 4GL. b. older file-oriented systems written in COBOL. c. manual double-entry bookkeeping systems. d. transaction processing systems in Fortune 100 companies. e. database systems in Fortune 100 companies.

b. older file-oriented systems written in COBOL.

12. Entity integrity in the relational model means that a. duplicate columns are not allowed b. the primary key must not be null and must be unique c. non-key attributes cannot be null d. foreign keys must exist in every entity table e. every entity must have a composite primary key

b. the primary key must not be null and must be unique

13. In the ____________ approach, each application created its own set of files regardless of existing files in other applications. a. database b. random access c. file-oriented d. double-entry e. events-oriented

c. file-oriented

11. In the relational model, if two tables are related a ____________ must exist in one of the tables. a. composite key b. concatenated key c. foreign key d. numeric field e. text field

c. foreign key

8. If a data set has only one unique identifier, that unique identifier becomes the __________ of the data set. a. foreign key b. secondary key c. primary key d. non-key attribute e. integrity constraint

c. primary key

10. In a database system _____________ prevents multiple users from updating the same data item simultaneously. a. static backup b. dynamic backup c. RAID d. concurrency control e. validation rule

d. concurrency control

1. Which of the following is NOT an advantage of the database approach in contrast to the file-oriented approach? a. data redundancy virtually eliminated. b. data independence. c. rapid application development due to sharing of data structures between applications. d. greater potential for data inconsistencies. e. reduction in data storage costs.

d. greater potential for data inconsistencies.

20. In the database approach, data structure definitions are handled by a. application programs. b. the operating system. c. hashing routines. d. the database management system. e. computer operators.

d. the database management system.

19. Which of the following are rules for relations in the relational model? a. duplicate rows and columns are not allowed b. relation names must be unique c. the first column in every table must be the primary key d. all of the above e. a and b

e. a and b

6. Which of the following is true regarding referential integrity in the relational model? a. a foreign key can have a null value when it is a non-key attribute b. if a foreign key has a value, it must match a value in the "master" table for that foreign key c. a foreign key must always have a value, even when it is a non-key attribute d. all of the above e. a and b

e. a and b

17. In a table, a validation rule that checks whether entries in a field conform to one of a set of acceptable values is referred to as a a. length test b. range test c. field test d. valid combinations test e. validity test

e. validity test