ch 6

A table that has all key attributes defined, no repeating groups, and an identified primary key is said to be in ____.

1NF

All relational tables satisfy the ____ requirements. a. 1NF b. 2NF c. BCNF d. 3NF

1NF

From a structural point of view, 2NF is better than ____.

1nf

A table that is in 1NF and includes no partial dependencies is said to be in ____. a. 1NF b. 2NF c. 3NF d. 4NF

2NF

A table whose primary key consists of only a single attribute is automatically in ____ when it is in 1NF. a. 2NF b. 3NF c. 4NF d. BCNF

2NF

25. A table in ____ contains no transitive dependencies. a. 1NF b. 2NF c. 3NF d. none of the above

3NF

A table that is in 2NF and contains no transitive dependencies is said to be in ____. a. 1NF b. 2NF c. 3NF d. 4NF

3NF

Assume the following table definition and dependencies. In which normal form is this table? TABLE(A, B, C, D) A + B --> C, D C --> B

3NF

For most business database design purposes, ____ is as high as you need to go in the normalization process.

3NF

Tables in ____ will perform suitably in business transactional databases.

3NF

A table where all attributes are dependent on the primary key and are independent of each other, and no row contains two or more multivalued facts about an entity, is said to be in ____.

4NF

____ yields increased performance in a database system.

Denormalization

____ refers to the level of detail represented by the values stored in a table's row.

Granularity

29. Which of the following would be the best name for a column representing the charges per hour in a table named JOB? a. JOB_CHG_HOUR b. CHG_HR c. CHARGES_PER_HOUR_FOR_JOB d. CHARGES_PER_HOUR

JOB_CHG_HOUR

____ keys are usually numeric, they are often automatically generated by the DBMS, they are free of semantic content (they have no special meaning), and they are usually hidden from the end users. a. Surrogate b. Foreign c. Composite d. Candidate

Surrogate

Improving ____ leads to more flexible queries. a. atomicity b. derived attributes c. normalization d. denormalization

a. atomicity

A table is in fourth normal form (4NF) if ____. a. all attributes are dependent on the primary key b. no column contains the same values c. it is in 3NF and there are no repeating groups d. it is in 3NF and has no independent multivalued dependencies

a. it is in 3NF and has no independent multivalued dependencies

When designing a database you should ____.

a. make sure entities are in normal form before table structures are created

Identification of the ____ will let you know where you are in the normalization process.

a. normal form

A table that displays data redundancies yields ____.

anomalies

The normalization process involves assigning ____ to tables based on the concept of determination.

attributes

In a normalized database, what is represented by each table?

b. a single subject

Lower normalization forms occur (and are even required) in specialized databases known as ____.

b. data warehouses

Most designers consider Boyce-Codd normal form (BCNF) as a special case of ____.

c. 3NF

Assume you have the following table definition: 1NF (PROJ_NUM, EMP_NUM, PROJ_NAME, EMP_NAME, JOB_CLASS, CHG_HOURS, HOURS). Identify a transitive dependency. a. PROJ_NUM --> PROJ_NAME b. JOB_CLASS --> CHG_HOURS c. EMP_NUM --> EMP_NAME, JOB_CLASS, CHG_HOURS d. PROJ_NUM, EMP_NUM --> PROJ_NAME, EMP_NAME, JOB_CLASS, CHG_HOURS

c. JOB_CLASS --> CHG_HOURS

BCNF can be violated only if the table contains more than one ____ key.

c. candidate

A ____ key makes it more difficult to write search routines.

c. composite primary

Data redundancy produces ____.

c. data integrity problems

When a table contains only one ____ key, the 3NF and the BCNF are equivalent.

candidate

The conflicts between design efficiency, information requirements, and performance are often resolved through ____.

compromises that may include denormalization

In an ideal (database design) world, the level of desired granularity is determined at the ____ design or at the requirements gathering phase.

conceptual

A table where every determinant is a candidate key is said to be in ____.

d. BCNF

A(n) ____ attribute is not part of a key. a. prime b. assigned c. nonprime d. composite

d. nonprime

Assume you have the following table: JOB_CODE JOB_DESCRIPTION JOB_CHG_HOUR 511 Programmer $35.75 512 Programmer $35.75 How might you eliminate the possibility of duplicate entries for JOB_DESCRIPTION?

d. use a unique index for JOB_DESCRIPTION

Storing a(n) ____ attribute in a table makes it easy to write the application software to produce the desired results.

derived

A ____ is any attribute whose value determines other values within a row. a. secondary key b. determinant c. partial dependency d. transitive dependency

determinant

In BCNF, every ____ in a table is a candidate key.

determinant

Dependencies can be depicted with the help of a dependency ____. a. form b. database c. schema d. diagram

diagram

35. In a real-world environment, we must strike a balance between design integrity and ____.

flexibility

Another name for a prime attribute is a ____ attribute. a. index b. surrogate c. view d. key

key

Dependencies based on only a part of a composite primary key are called ____ dependencies. a. primary b. composite c. partial d. incomplete

partial

An attribute that is part of a key is known as a(n) ____ attribute. a. important b. entity c. nonprime d. prime

prime

The ____ model views the data as part of a table or collection of tables in which all key values must be identified. a. relational b. external c. object-oriented d. conceptual

relational

To implement a surrogate key, MS Access uses an AutoNumber data type, MS SQL Server uses an identity column, and Oracle uses a(n) ____ object.

sequence

A ____ key is an artificial PK introduced by the designer with the purpose of simplifying the assignment of primary keys to tables. a. surrogate b. foreign c. composite d. candidate

surrogate

Given the following table definition, how many tables would be produced by the conversion to 2NF? 1NF (PROJ_NUM, EMP_NUM, PROJ_NAME, EMP_NAME, JOB_CLASS, CHG_HOURS, ASSIGN_HOURS) a. one b. two c. three d. four

three

23. A 2NF table can exhibit ____ dependency. a. partial b. indirect c. complete d. transitive

transitive

Assume the following table definition and dependencies. How many tables would be produced by converting to BCNF? TABLE(STU_ID, STAFF_ID, CLASS_CODE, ENROLL_GRADE) STU_ID + STAFF_ID --> CLASS_CODE, ENROLL_GRADE CLASS_CODE --> STAFF_ID

two

Unnormalized tables yield no simple strategies for creating virtual tables, which are also known as ____.

views