Database Test 1

relationship

A verb associating two nouns in a business rule translates to a

many-to-many

Students and classes have a

CHAR

U.S. state abbreviations are always two characters, so ____________________(2) is a logical choice for the data type representing a state column.

create index

Using the ____________________ command, SQL indexes can be created on the basis of any selected attribute

logical

When you can change the internal model without affecting the conceptual model, you have ___________independence

reserved

words are words used by SQL to perform specific functions.

index

A common practice is to create a(n) ____________________ on any field that is used as a search key, in comparison operations in a conditional expression, or when you want to list rows in a specific order.

entity

A noun in a business rule translates to a

single-valued simple

A person's social security number would be an example of a(n) ____________________ attribute.

Boolean

A specialty field in mathematics, known as ____________________ algebra, is dedicated to the use of logical devices

DROP

A table can be deleted from the database by using the

Drop

A table can be deleted from the database by using the ____________________ command

existence

A weak entity must be ____________________-dependent

derived

A(n) ____________________ attribute need not be physically stored within the database

wild card

A(n) ____________________ character is a symbol that can be used as a general substitute for other characters or commands

schema

A(n) ____________________ is a group of database objects, such as tables and indexes, that are related to each other.

join

A(n) ____________________ is performed when data is retrieved from more than one table at a time.

cascading

A(n) ____________________ order sequence can be created easily by listing several attributes, separated by commas, after the ORDER BY clause

binary

A(n) ____________________ relationship exists when two entities are associated

strong

A(n) ____________________ relationship is also known as an identifying relationship.

subquery

A(n) ____________________, also known as a nested query or an inner query, is a query that is embedded (or nested) inside another query

recursive

An alias is especially useful when a table must be joined to itself in ____________________ queries.

multivalued

An attribute representing one or more college degrees belonging to a person would be a(n) ____________________ attribute

business

Connectivities and cardinalities are usually based on ____________________ rules

Oracle

DATE() and SYSDATE are special functions that return today's date in MS Access and ____________________, respectively

attribute

Each column in a relation represents

tuple

Each row in a relation is called

participation

Failure to understand the distinction between mandatory and optional ____________________ in relationships might yield designs in which awkward (and unnecessary) temporary rows (entity instances) must be created just to accommodate the creation of required entities

GROUP BY

Frequency distributions can be created quickly and easily using the SQL ____________________ clause.

relationships

Identifying the attributes of the entities helps you better understand the ____________________ among entities.

null

If you add a new column to a table that already has rows, the existing rows will default to a value of ____________________ for the new column

small int

If your integer values are relatively small, use ____________________ instead of INT

small circle O

In Crow's Foot notation, an optional relationship between entities is shown by drawing a(n) ____________________ on the side of the optional entity

conditional

In SQL, all ____________________ expressions evaluate to true or false.

1

In a 1:M relationship, you must always create the table for the ____________________ side first.

query

In the SQL environment, the word ____________________ covers both questions and actions

attributes

In the original ERM described by Chen, relationships do not contain ____________________.

existence-dependent

In the relationship "EMPLOYEE claims DEPENDENT" the DEPENDENT entity is ____________________ on the EMPLOYEE entity

derived

Instead of storing a person's age, it is better to store the date of birth and use the difference between that value and the system date as a(n) ____________________ attribute

relational data model

MySQL is an example of a

optional

Participation is ____________________ if one entity occurrence does not require a corresponding entity occurrence in a particular relationship.

participation

Relationship strength depends on how the primary key of the related entity is formulated, while the relationship ____________________ depends on how the business rule is written

conceptual

The Chen model is specially useful to illustrate some of the ____________________ elements of database design

implementation

The Crow's Foot model is more ____________________-oriented than the Chen model

solid

The Crow's Foot notation depicts the strong relationship with a(n) ____________________ line between the entities

ERD

The ERM forms the basis of a(n) ____________________

ER model

The ____________________ refers to a specific table row as an entity instance

HAVING

The _____________________ clause of the GROUP BY statement operates very much like the WHERE clause in the SELECT statement

100

The basic SQL vocabulary has a fewer than ____________________ words.

EXISTS

The special operator used to check whether a subquery returns any rows is

Drop index

To delete an index, use the ____________________ command

Entity relationship

Which data model has the highest level of abstraction

constraint

Which of the following is a basic building block of all data models

database creation

With the exception of the ____________________ process, most RDBMS vendors use SQL that deviates little from the ANSI standard SQL.

attribute names

You can indicate just the attributes that have required values by listing the ____________________ inside parentheses after the table name

Composite

____________________ attributes can be subdivided.

Attributes

are characteristics of entities

Constraints

are normally expressed in the form of rules

Primary keys

are underlined in an ER diagram

simple

attribute cannot be subdivided

DROP

command is used with the ALTER TABLE command to modify the table by deleting a column

SELECT

coupled with appropriate search conditions, is an incredibly powerful tool that enables you to transform data into information

subachema

defines the portion of the database "seen" by the application programs that produce information from the data

segment

in a hierarchical model is the equivalent of a record in a file system

class

is a collection of similar objects with a shared structure and behavior

UML

is a language based on OO concepts that describes a set of diagrams and symbols used to graphically model a system

relational diagram

is a representation of the relational database's entities, the attributes within those entities and the relationships between those entities

entity

is anything about which data are to be collected and stored

domain

is the attribute's set of possible values

schema

is the conceptual organization of the entire database as viewed by the database administrator.

attribute

is the equivalent of a field in a file system

logical design

is used to refer to the task of creating a conceptual data model that could be implemented in any DBMS.

object-oriented

model uses the concept of inheritance

entity relationship

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

DML

that defines the environment in which data is to be managed

hierarchical

the basic logical structure is represented as an upside-down tree

network

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