Chapter 4 Questions

How does the database approach solve the problem of data redundancy?

Data redundancy is not a problem with the database approach because individual data elements need to be stored only once yet be available to multiple users.

What is a database authorization table?

The database authorization table contains rules that limit the actions a user can take. Each user is granted certain privileges that are coded in the authority table, which is used to verify the user's action requests.

Why are the hierarchical and network models called navigational databases?

These are called navigational models because traversing or searching them requires following a predefined path which is established through explicit linkages between related records.

Which of the following is a characteristic of a relational database system? a. User views limit access to the database. b. Database navigation follows explicit links that are contained within the records. c. All users share all the data to achieve integration of functions. d. No two users share the same user view.

a. User views limit access to the database.

Which of the following is not an access control in a database system? a. antivirus software b. database authorization table c. passwords d. voice prints

a. antivirus software

Database tables should be normalized. This means a. each attribute in a row should be dependent on the primary key and independent of other attributes in the table. b. each attribute in a row should be independent of the primary key and dependent on other attributes in the table. c. each attribute in a row should contain a unique in its value. d. the value of each attribute should fall within a normal range of values predetermined for that attribute. e. both a and d are correct.

a. each attribute in a row should be dependent on the primary key and independent of other attributes in the table.

The data definition language a. identifies, for the database management system, the names and relationships of all data elements, records, and files that comprise the database b. inserts database commands into application programs to enable standard programs to interact with and manipulate the database c. permits users to process data in the database without the need for conventional programs d. describes every data element in the database

a. identifies, for the database management system, the names and relationships of all data elements, records, and files that comprise the database

A description of the physical arrangement of records in the database is a. the internal view b. the conceptual view c. the subschema d. the external view

a. the internal view

For those instances where individual users may be granted summary and statistical query access to confidential data to which they normally are denied access, which type of control is most suitable? a. User-defined procedures b. Data encryption c. Inference controls d. Biometric devices

c. Inference controls

Which of the following statements does not apply to the database approach? a. Database systems have data independence; that is, the data and the programs are maintained separately, except during processing. b. Database management systems employ a data definition language that helps describe each schema and subschema. c. The database administrator is the part of the software package that instructs the operating aspects of the program when data are retrieved. d. A primary goal of database systems is to minimize data redundancy. e. Database systems are based on the philosophy of data ownership.

c. The database administrator is the part of the software package that instructs the operating aspects of the program when data are retrieved.

An inventory table in a relational database system contains values for items such as part number, part name, description, color, and quantity. These individual items are called a. entities. b. record types. c. attributes. d. occurrences.

c. attributes.

In the relational database model all of the following are true except a. data is presented to users as tables b. data can be extracted from specified rows from specified tables c. a new table can be built by joining two tables d. only one-to-many relationships can be supported

d. only one-to-many relationships can be supported

The data attributes that a particular user has permission to access are defined by the a. operating system view. b. systems design view. c. database schema. d. user view. e. application program.

d. user view.

Database currency is achieved by a. implementing partitioned databases at remote sites. b. employing data-cleansing techniques. c. ensuring that the database is secure from accidental entry. d. an external auditor's reconciliation of reports from multiple sites. e. a database lockout that prevents multiple simultaneous access.

e. a database lockout that prevents multiple simultaneous access.

What does allow users to retrieve and modify data easily?

query language

What types of problems do data redundancy cause?

a. increased data storage because the same data is stored in multiple files b. increased data updating because changes must be made to multiple files c. problem of current data in some files, but not all files

Where are database access permission defined? a. Operating system b. Database authority table c. Database schema d. Systems manual e. Application programs

b. Database authority table

The advantages of a partitioned database include all of the following except a. user control is enhanced b. data transmission volume is increased c. response time is improved d. risk of destruction of entire database is reduced

b. data transmission volume is increased

A database system that has several remote users networked together, but each user site stores a unique portion of the database is called a a. replicated data processing network. b. partitioned database. c. recentralized network. d. multi-drop data network. e. hybrid system.

b. partitioned database.

Which of the following is not a problem usually associated with the flat-file approach to data management? a. data redundancy b. restricting access to data to the primary user c. data storage d. currency of information

b. restricting access to data to the primary user

Which of the following is a characteristic of a relational database system? a. Tables are linked to other related table through explicit pointers. b. A parent table may be related to many child tables, but a child table may have only one parent. c. Each table must contain an attribute whose value is unique. d. Tables in 1:M associations are linked by embedding the primary key of the M side tables into the 1 side table as a foreign key.

c. Each table must contain an attribute whose value is unique.

Which term is not associated with the relational database model? a. tuple b. attribute c. collision d. relation

c. collision

Which procedure will prevent two end users from accessing the same data element at the same time? a. data redundancy b. data replication c. data lockout d. none of the above

c. data lockout

Replicated databases are most effective when a. users in the system do not need to share common data. b. primary users of the data are clearly identifiable. c. read-only access is needed at each site. d. all of the above.

c. read-only access is needed at each site.

Which duty is not the responsibility of the database administrator? a. to develop and maintain the data dictionary b. to implement security controls c. to design application programs d. to design the subschema

c. to design application programs

Which of the following is not a basic database backup and recovery feature? a. checkpoint b. backup database c. transaction log d. database authority table

d. database authority table

The functions of a database administrator are a. database planning, data input preparation, and database design. b. data input preparation, database design, and database operation. c. database design, database operation, and equipment operations. d. database design, database implementation, and database planning. e. database operations, database maintenance, and data input preparation.

d. database design, database implementation, and database planning.