Midterm

Which of the following types of HDFS nodes acts as the interface between the user application and the HDFS?

Client node

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 consistentently?

Data redundancy

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

False

An advantage of database systems is that you needn't perform frequent updates and apply latest patches.

False

Field refers to a collection of related records.

False

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

False

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

False

The conceptual model can handle _____ relationships and multivalued attributes.

M:N

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

SELECT

Which of the following is true of NoSQL databases?

They are not based on the relationship model.

Which of the following is true of business rules? [beginning of Ch. 2]

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

Which of the following is true of spreadheet applications.

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

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

True

Data constitute the building blocks of information.

True

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

True

M:N relationships are not appropriate in a relational model.

True

_____ are normally expressed in the form of rules.

constraints

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

domain

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

entity

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

entry relationship

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

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

integrity

According to Codd's _____ rule of relational databases, if the system supports low-level access to the data, users must not be allowed to bypass the integrity rules of the database.

nonsubversion

End-user data is _______.

raw facts of interest to the end user.

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

record

A(n) _____ is bidirectional.

relationship

An XML database supports the storage and management of _____ XML data.

semistructured

In the entity relationship diagram (ERD), cardinality is indicated using the _____ notation, where max is the maximum number of associated entities and min represents the minimum number of associated entities.

(min, max)

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

Data integrity

Composite attributes make it easier to facilitate detailed queries.

False

Data is the result of processing raw facts to reveal its meaning.

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

False

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

False

The external model is the representation of the database as "seen" by the DBMS.

False

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

False

A ______ is a collection of related records.

File

_____ are especially useful when you are trying to determine what values in related tables cause referential integrity problems.

Outer joins

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

Predicate

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

SELECT

A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.

True

A data warehouse can store data derived from many sources.

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

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

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

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

True

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

True

Structure is based on the type of processing to be performed on the data.

True

The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.

True

The network model has structural level dependence.

True

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

True

To implement a small database, a database designer must know the "1" and the "M" sides of each relationship and whether the relationships are mandatory or optional.

True

Today, most relational database products can be classified as object/relational. [end of Ch. 2]

True

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

True

The _____ notation of entity-relationship modelling can be used for both conceptual and implementation modelling.

UML

______ data exist in the format in which they were collected.

Unstructured

_______ data exist in a format that does not lend itself to processing that yields information.

Unstructured

Another name for a composite entity is a(n) _____ entity.

bridge

A(n) _______ enables a database administrator to describe schema components.

data definition language (DDL)

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

data dictionary

The decision to store _____ attributes in database tables depends on the processing requirements and the constraints placed on a particular application.

derived

A(n) ________ database is used by an organization and supports many users across many departments. [end of Ch. 1]

enterprise

A relationship is an association between _____.

entities

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

entity

Knowing the minimum and maximum number of _____ occurrences is very helpful at the application software level.

entity

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

keys

According to Codd's _____ rule of relational databases, 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

The _____ data model uses the concept of inheritance.

object-oriented

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

one

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

query result set

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

relationship

A desktop database is a _____ database.

single-user

If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as a(n) _____ entity.

strong

A _____ is any key that uniquely identifies each row.

superkey

In a database context, a(n) _____ indicates the use of different names to describe the same attribute.

synonym

Data is said to be verifiable if:

the data always yields consistent results.

A _____ relationship exists when an association is maintained within a single entity.

unary