Exam 2

True

A candidate key is an attribute, or combination of attributes, that uniquely identifies a row in a relation

1. the key must uniquely identify the row 2. the key must be nonredundant 3. each nonkey attribute is functionally dependent upon it

A candidate key must satisfy all of the following conditions

Integrity Constraints

A domain definition consists of the following components EXCEPT

True

A partial functional dependency is a functional dependency in which one or more nonkey attributes are functionally dependent on part (but not all) of the primary key.

True

A range control limits the set of permissible values that a field may assume

True

A referential integrity constraint is a rule that maintains consistency among the rows of two relations

False

A relation is in first normal form if it has no more than one multivalued attribute

Second Normal Form

A relation that contains no multivalued attributes and has nonkey attributes solely dependent on the primary key but contains transitive dependencies is in which normal form?

Referential Integrity Constraint

A rule that states that each foreign key value must match a primary key value in the other relation is called the

False

A transversal dependency is a functional dependency between two or more nonkey attributes

True

A well-structured relation contains minimal redundancy and allows users to manipulate the relation without errors or inconsistencies.

Pointer

A(n) ________ is a field of data used to locate a related field or record

A one-to-many relationship

All of the following are common denormalization opportunities EXCEPT

use a lot of storage space

All of the following are objectives when selecting a data type EXCEPT

Boolean

All of the following are valid datatypes in Oracle 11g EXCEPT

True

All values that appear in a column of a relation must be taken from the same domain

Efficiency

An advantage of partitioning is

False

An anomaly is a type of flaw in the database server

Range Control

An integrity control supported by a DBMS is

False

Anomalies do not generally arise out of transitive dependencies

True

Clustering allows for adjacent secondary memory locations to contain rows from several tables.

Transaction Volumes

Database access frequencies are estimated from

False

Denormalization is the process of transforming relations with variable-length fields into those with fixed-length fields

Horizontal Partitioning

Distributing the rows of data into separate files is called

Checking to see if missing data will greatly impact results

Sensitivity testing involves

Default Value

The value a field will assume unless the user enters an explicit value for an instance of that field is called a(n):

you must be able to check the output of a CASE tool.

Understanding the steps involved in transforming EER diagrams into relations is important because

False

Unlike columns, the rows of a relation may not be interchanged and must be stored in one sequence

False

When transforming a unary many-to-many relationship to relations, a recursive foreign key is used

False

When transforming a weak entity, one should create one relation with both the attributes of the strong entity and the attributes of the weak entity

True

A cascading delete removes all records in other tables associated with the record to be deleted

1. Fast data retrieval 2. security 3. efficient storage

A factor to consider when choosing a file organization is

False

A file organization is a named portion of primary memory

True

A foreign key is a primary key of a relation that also is a primary key in another relation.

Physical

A form of database specification that indicates all the parameters for data storage that are then input to database implementation is

Transitive Dependency

A functional dependency between two or more nonkey attributes is called a

False

A key is a data structure used to determine the location of rows in a file that satisfy some condition

1. substitute and estimate for the missing data 2. track missing data with special reports 3. perform sensitivity testing

A method for handling missing data is to

1. normalized relations 2. definitions of each attribute 3. technology descriptions

A requirement to begin designing physical files and databases is

when different categories of a table's rows are processed separately

Horizontal partitioning makes sense when

True

If an identifier is not assigned, the default primary key for an associative relation consists of the two primary key attributes from the other two relations.

False

In the relational data model, associations between tables are defined through the use of primary keys

False

Indexes are most useful on small, clustered files

True

Keeping the zip code with the city and state in a table is a typical form of denormalization

1. minimize data redundancy 2. simplify the enforcement of referential integrity 3.make it easier to maintain data

Main goals of Normalization

Data Accessibility, Response Time & Security

Physical database design decisions must be made carefully because of impacts on

False

Reduced uptime is a disadvantage of partitioning.

True

Security is one advantage of partitioning

Entity Integrity Rule

The ________ states that no primary key attribute may be null

True

The allowable range of values for a given attribute is part of the domain constraint

Determinant

The attribute on the left-hand side of the arrow in a functional dependency is the

True

The columns of a relation can be interchanged without changing the meaning or use of the relation

no primary key attribute can be null

The entity integrity rule states that

False

The entity integrity rule states that a primary key attribute can be null

Data Structure, Data Manipulation & Data Integrity

The relational data model consists of which components?

Field

The smallest unit of application data recognized by system software is a

First Normal Form

When all multivalued attributes have been removed from a relation, it is said to be in

True

When normalizing, the goal is to decompose relations with anomalies to produce smaller, well-structured relations

False

When transforming a one-to-one relationship, a new relation is always created

1. Each attribute has a unique name 2.No two rows in a relation are identical 3.There are no multivalued attributes in a relation

Which of the following are properties of relations?

Improve Data Integrity

Which of the following is an objective of selecting a data type

operating system

While Oracle has responsibility for managing data inside a tablespace, the tablespace as a whole is managed by the

Data Integrity

________ is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated.