Midterm CIS 1200 S

The relational data model was developed in the ____.

1970s

The object-oriented data model was developed in the ____.

1980s

The ____ relational type is the "relational model ideal."

1:M

____ are important because they help to ensure data integrity.

Constraints

The ____ serve(s) as the intermediary between the user and the database.

DBMS

A ____ contains at least all of the attribute names and characteristics for each table in the system.

Data dictionary

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

Data inconsistency

The phrase ____ refers to an organization of components that define and regulate the collection, storage, management and use of data within a database environment.

Database system

A ____ database supports data distributed across several different sites.

Distributed

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

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

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

Entity

The ____ model uses the term connectivity to label the relationship types.

Entity relationship

The ____ model is the end users' view of the data environment.

External

A query language is a procedural language.

False

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

False

All simple attributes are also single-valued.

False

An ERM is dependent on the database type.

False

Attributes have a domain that specifies the data type of the attribute.

False

Because the relational model uses attribute values to establish relationships among tables, many database users correctly assume that the term relation refers to such relationships.

False

Corporations use only structured data.

False

Data and information are essentially the same thing.

False

Data modeling starts with a very complex representation, and as knowledge of the problem is gained, the model is simplified.

False

Database designers determine the data and information that yield the required understanding of the entire business.

False

In Chen notation, there is no way to represent cardinality.

False

In a relational model, if A determines B, C, and D, you write A = B, C, D.

False

One disadvantage of the DBMS is that it increases the risk of data security breaches.

False

Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data. Question options:

False

The Crow's Foot model is less implementation-oriented than the Chen model.

False

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

False

The SELECT operator yields a vertical subset of a table.

False

The hierarchical model is software-independent.

False

There is never a good reason to use null values in a database.

False

n an ER diagram, primary keys are usually bolded.

False

Accurate, relevant, and timely information is the key to ____.

Good decision making

A(n) ____ is an ordered arrangement of keys and pointers.

Index

____ is used to reveal the meaning of data

Information

The organization of the data within the folders in a manual file system was determined by ____.

Its expected use

Date attributes contain calendar dates stored in a special format known as the ____ date format.

Julian

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

Keys

Codd's Rule of ____ states: Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns).

Logical Data Independence

Students and classes have a ____ relationship.

Many-to-many

____ provide(s) a description of the data characteristics and the set of relationships that link the data found within the database.

Metadata

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

Model

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

NOT NULL

A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s).

Natural

All primary key entries are unique, and no part of a primary key may be ____.

Null

In an outer join, the matched pairs would be retained and any unmatched values in the other table would be left ____.

Null

The ____ data model uses the concept of inheritance.

Object oriented

____ is a set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from the data warehouse.

Online analytical processing

Most decision-support data are based on historical data obtained from ____.

Operational

____ relates to the activities that make the database perform more efficiently in terms of storage and access speed.

Performance tuning

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

Predicate

The response of the DBMS to a query is the ____.

Query result set

A ____ is a logically connected set of one or more fields that describes a person, place, or thing.

Record

Controlled ____ makes a relational database work.

Redundancy

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

Relationship

A(n) ____ is bidirectional.

Relationship

____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.

SELECT

Most data you encounter is best classified as ____.

Semistructured

____ data are the result of formatting to facilitate storage, use and generation of information.

Structured

A ____ is any key that uniquely identifies each row.

Superkey

The relational model's creator, E. F. Codd, used the term relation as a synonym for ____.

Table

Which of the following is true of business rules?

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

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

True

A data dictionary contains metadata—data about data.

True

A data model is usually graphical.

True

A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table

True

A relationship is identified by a name that describes the relationship.

True

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

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

Business rules must be rendered in writing.

True

Current relational database software generally provides only a system catalog (and not a data dictionary)

True

Data constitute the building blocks of information.

True

Data processing can be as simple as organizing data to reveal patterns.

True

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

True

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

True

In the original Chen model, each attribute is represented using an oval with the attribute name connected to the entity with a line.

True

M:N relationships are not appropriate in a relational model

True

Metadata present a more complete picture of the data in the database than the data itself.

True

Numeric data are data on which you can perform meaningful arithmetic procedures.

True

RDBMSs enforce integrity rules automatically.

True

Tables within a database share common attributes that enable the tables to be linked together.

True

The DBMS can easily handle multivalued attributes.

True

The DIFFERENCE operator subtracts one table from the other.

True

The ER model refers to a specific table row as an entity instance.

True

The ER model refers to a specific table row as an entity occurrence.

True

The network model has structural level dependence.

True

The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage

True

The same data might be simultaneously structured and unstructured depending on the intended processing.

True

____ combines all rows from two tables, excluding duplicate rows.

UNION

Oracle 11g is an example of a(n) ____.

XML/Hybrid data model

A(n) ____ enables a database administrator to define schema components.

data definition language (DDL)

The attribute B is ____ the attribute A if each value in column A determines one and only one value in column B.

functionally dependent on

In the ____ model, the basic logical structure is represented as an upside-down tree.

hierarchical

In a database context, the word ____ indicates the use of the same attribute name to label different attributes.

homonym

Since it is used to link the tables that originally were related in a M:N relationship, the composite entity structure includes—as foreign keys—at least the ____ keys of the tables that are to be linked.

primary

A ____ key is defined as a key that is used strictly for data retrieval purposes.

secondary

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

transactional