CIS 205 Final study guid

The relational data model was developed in the _____.

1970s

The _____ relationship should be rare in any relational database design.

1:1

_____ exists when different versions of the same data appear in different places.

Data inconsistency

Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

False

Character data can contain any character or symbol intended for mathematical manipulation.

False

Data and information are essentially the same thing.

False

Data anomaly is defined as the condition in which all of the data in the database are consistent with the real-world events and conditions.

False

The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.

False

_____ returns only the attributes requested, in the order in which they are requested.

PROJECT

If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

True

In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first.

True

In an SQL-based relational database, rows in different tables are related based on common values in common attributes.

True

A(n) _____ might be written by a programmer or it might be created through a DBMS utility program.

application

A(n) _____ is the equivalent of a field in a file system.

attribute

A _____ key can be described as a minimal superkey, a superkey without any unnecessary attributes.

candidate

The database structure in a DBMS is stored as a _____.

collection of files

Each table _____ represents an attribute.

column

A _____ attribute can be further subdivided to yield additional attributes.

composite

The entity relationship diagram (ERD) represents the _____ database as viewed by the end user.

conceptual

A(n) _____ is a restriction placed on the data.

constraint

_____ are important because they help to ensure data integrity.

constraints

A(n) _____ is the set of possible values for a given attribute.

domain

A(n) _____ database is used by an organization and supports many users across many departments.

enterprise

A relationship is an association between _____.

entities

A noun in a business rule translates to a(n) _____ in the data model.

entity

A(n) _____ is anything about which data are to be collected and stored.

entity

A _____ is a character or group of characters that has a specific meaning.

field

A _____ is a collection of related records.

file

A _____ is the primary key of one table that has been placed into another table to create a common attribute.

foreign key

The first step in building an entity-relationship diagram (ERD) is _____.

identifying the business rules based on the description of operations

In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable.

keys

Students and classes have a _____ relationship.

many-to-many

A(n) _____'s main function is to help one understand the complexities of the real-world environment.

model

Ideally, an entity identifier is composed of _____ attribute(s).

one

If Tiny College has some departments that are classified as "research only" and do not offer courses, the COURSE entity of the college database would be _____ the DEPARTMENT entity.

optional to

_____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.

predicate

End-user data is _____.

raw facts of interest to the end user

If an employee within an EMPLOYEE entity has a relationship with itself, that relationship is known as a _____ relationship.

recursive

MySQL is an example of the _____.

relational data model

A verb associating two nouns in a business rule translates to a(n) _____ in the data model.

relationship

A(n) _____ is bidirectional.

relationship

A _____ attribute is one that cannot be subdivided.

simple

A person's Social Security number would be an example of a(n) _____ attribute.

single valued

The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column.

NOT NULL

In the entity relationship model, a table row corresponds to an entity instance.

True

The DIFFERENCE operator subtracts one table from the other.

True

The only way to access the data in a database is through the DBMS.

True

Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

True

You can think of a table as a persistent representation of a logical relation.

True

An entity is said to be _____-dependent if it can exist in the database only when it is associated with another related entity occurrence.

existence

A(n) _____ database supports a relatively small number of users (usually fewer than 50) or a specific department within an organization.

workgroup

Which of the following refers to the situation where different versions of the same data are stored at different places because they weren't updated consistently?

Data redundancy

A(n) _____ attribute is an attribute that must have a value.

Derived attribute

Field refers to a collection of related records.

False

In an SQL-based relational database, each table is dependent on every other table.

False

Only a single attribute, not multiple attributes, can define functional dependence.

False

Relationships between entities always operate in one direction.

False

The DBMS reveals much of the database's internal complexity to the application programs and users.

False

The order of the rows and columns is important to the DBMS.

False

The relational model is hardware-dependent and software-independent.

False

The row's range of permissible values is known as its domain.

False

_____ are underlined in an ER diagram.

Identifiers

_____ is the result of revealing the meaning of raw facts.

Information

_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

M:N

To be considered minimally relational, the DBMS must support the key relational operators _____, PROJECT, and JOIN.

SELECT

Which of the following is true of business rules?

They can serve as a communication tool between the users and designers.

Which of the following is true of spreadsheet applications?

They enhance the user's ability to understand the data.

A composite identifier is a primary key composed of more than one attribute.

True

A data model is usually graphical.

True

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

True

A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

True

An entity in the entity relationship model corresponds to a table in the relational environment.

True

An implementation-ready data model should contain a description of the data structure that will store the end-user data.

True

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

True

Data constitute the building blocks of information.

True

Each row in the relational table is known as an entity instance or entity occurrence in the ER model.

True

Each table in a relational database must have a primary key.

True

In the Chen and Crow's Foot notations, an entity is represented with a rectangle containing the entity's name.

True

In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.

True

In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an entity rectangle with a line.

True

Metadata describe the data characteristics and the set of relationships that links the data found within the database.

True

One disadvantage of a database system over previous data management approaches is increased costs.

True

Relational algebra defines the theoretical way of manipulating table contents using relational operators.

True

A(n) _____ represents a particular type of object in the real world.

entity

A(n) _____ only returns matched records from the tables that are being joined.

inner join

Referential _____ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null.

integrity

Database design is a(n) _____ process based on repetition.

iterative

A(n) _____ process is based on repetition of processes and procedures.

iterative process

A _____ is any key that uniquely identifies each row.

superkey

The _____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.

system catalog

Data is said to be verifiable if:

the data always yields consistent results.