COP3703 Database Concepts

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

application

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

bridge

From a database point of view, the collection of data becomes meaningful only when it reflects properly defined _____

business rules

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 conflicts between design efficiency, information requirements, and performance are often resolved through _____

compromises that include denormalization

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

conceptual

A derived attribute is indicated in the Chen notation by a _____ that connects the attribute and an entity

dashed line

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

data dictionary

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

database system

From a system functionality point of view, _____ attribute values can be calculated when they are needed to write reports or invoices

derived

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

derived

In the context of total completeness, in a(n) _____, every supertype occurrence is a member of only one subtype

disjoint constraint

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

domain

The extended entity relationship model (EERM) is sometimes referred to as the _____

enhanced entity relationship model

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

The purpose of a(n) _____ is to simplify an entity-relationship diagram (ERD) and thus enhance its readability

entity cluster

A primary key's main function is to uniquely identify a(n) _____ within a table

entity instance or row

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

entity relationship

The _____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text

entity relationship

The default comparison condition for the subtype discriminator attribute is the _____ comparison

equality

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

field

A _____ is a collection of related records

file

In a real-world environment, we must strike a balance between design integrity and _____

flexibility

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

foreign key

One of the limitations of the _____ model is that there is a lack of standards

hierarchical

In organizations that generate large number of transactions, _____ are often a top priority in database design

high processing speeds

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

homonym

Complex _____ requirements may dictate data transformations, and they may expand the number of entities and attributes within the design

information

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

A table is in 4NF if it is in 3NF, and _____

it has no multivalued dependencies

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

keys

When designing a database, you should _____

make sure that entities are in normal form before table structures are created

Students and classes have a _____ relationship

many-to-many

A _____ key is a real-world, generally accepted identifier used to uniquely identify real-world objects

natural

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

natural

Surrogate primary keys are especially helpful when there is no _____ key

natural

If one exists, a data modeler uses a _____ as the primary key of the entity being modeled

natural identifier

In the _____ model, the user perceives the database as a collection of records in 1:M relationships, where each record can have more than one parent

network

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

nonsubversion

1NF, 2NF, and 3NF are _____

normalization stages

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

one

The existence of a(n) _____ entity indicates that its minimum cardinality is zero

optional

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

In the context of total completeness, in a(n) _____, every supertype occurrence is a member of at least one subtype

overlapping constraint

The preferred placement for a foreign key when working with a 1:1 relationship is to _____

place the foreign key in one of the entities

One important inheritance characteristic is that all entity subtypes inherit their _____ key attribute from their supertype

primary

NoSQL databases

provide fault tolerance

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

recursive

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

secondary

A _____ attribute is one that cannot be subdivided

simple

When using the Crow's Foot notation, the associative entity is indicated by _____ relationship lines between the parents and the associative entity

solid

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(n) _____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related

subtype discriminator

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

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

system catalog

A _____ relationship exists when three entities are associated

ternary

Normalization works through a series of stages called normal forms. For most purposes in business database design, _____ stages are as high as you need to go in the normalization process

three

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

unary

When two or more tables share the same number of columns, and when their corresponding columns share the same or compatible domains, they are said to be _____

union-compatible

When you define a table's primary key, the DBMS automatically creates a(n) _____ index on the primary key column(s) you declared

unique

The "_____" characteristic of a primary key states that the primary key must uniquely identify each entity instance, must be able to guarantee unique values, and must not contain nulls

unique values

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

weak

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)

The relational data model was developed in the _____

1970s

At the implementation level, the supertype and its subtype(s) depicted in a specialization hierarchy maintain a(n) _____ relationship

1:1

The _____ relationship should be rare in any relational database design

1:1

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

1NF

For most business transactional databases, we should normalize relations into _____

3NF

To generate a surrogate key, Microsoft Access uses a(n) _____ data type

AutoNumber

_____ expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity

Cardinality

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

Client node

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

Julian

_____ is the body of information and facts about a specific subject

Knowledge

The conceptual model can handle _____ relationships and multivalued attributes

M:N

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities

M:N

_____ provide a description of the data characteristics and the set of relationships that link the data found within the database

Metadata

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

NOT NULL

Which of the following types of HDFS nodes stores all the metadata about a file system?

Name node

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

Outer joins

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

PROJECT

_____ relates to the activities that make the database execute transactions more efficiently in terms of storage and access speed

Performance tuning

_____ relationships occur when there are multiple relationship paths between related entities

Redundant

According to Codd's _____ rule of relational database, "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)."

Rule of Logical Data Independence

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

SELECT

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

SELECT

_____ are the result of formatting disorganized data in order to facilitate storage, use and generation of information

Structured data

_____ serve as the intermediary between the user and the database

DBMSs

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

Data inconsistency

_____ 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

_____ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely

Data warehouse

_____ data refer to data whose values change over time and for which one must keep a history of the data changes

Time-variant

_____ data exist in the format in which they were collected

Unstructured