Data Modeling Foundations
Good decision making
Accurate, relevant, and timely information is the key to ___.
null
No data entry at all is known as a ___.
file system data model
VMS/VSAM is an example of a(n) _____.
composite
A ___ attribute can be further subdivided to yield additional attributes.
simple
A ___ attribute is one that cannot be subdivided.
data dictionary
A ___ contains at least all of the attribute names and characteristics for each table in the system.
composite
A ___ identifier is composed of more than one attribute.
record
A ___ is a logically connected set of one or more fields that describes a person, place or thing.
superkey
A ___ is any key that uniquely identifies each row.
candidate
A ___ key can be described as a superkey without unnecessary attributes, that is, a minimal superkey.
secondary
A ___ key is defined as a key that is used strictly for data retrieval purposes.
person's age
A ___ should be a derived attribute.
singlevalued
A ____ attribute can have only one value.
file
A ____ is a collection of related records.
need not be stored physically
A derived attribute ____.
dashed line
A derived attribute is indicated in the Chen model by a ____.
entity
A noun in a business rule translates to a(n) ___ in the data model.
entities
A relationship is an association between ____.
relationship
A verb associating two nouns in a business rule translates to a(n) ___ in the data model.
multiuser
A workgroup database is a(n) ___ database.
workgroup
A(n) ___ database is used by an organization and supports many users across many departments.
entity
A(n) ___ is anything about which data are to be collected and stored.
relationship
A(n) ___ is bidirectional.
attribute
A(n) ___ is equivalent of a field file system.
entity
A(n) ___ represents a particular type of object in the real world.
enterprise
A(n) ____ database is designed to support a company's day-to-day operations.
constraint
A(n) ____ is a restriction placed on the data.
index
A(n) ____ is an ordered arrangement of keys and pointers.
table
A(n) ____ is perceived as a two-dimensional structure composed of rows and columns.
natural
A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s).
inner
A(n) ____ join only returns matched records from the tables that are being joined.
application program
A(n) ____ might be written by a programmer or it might be created through a DBMS utility program.
conceptual
A(n) ____ model represents a global view of the database as viewed by the entire organization.
(DDL) data definition language
A(n) _____ enables a database administrator to define schema components.
model
A(n) ______'s main function is to help you understand the complexities of the real-world environment.
M:N
Although the conceptual model can handle ____ relationships and multivalued attributes, you should not implement them in the RDBMS.
existence
An entity is said to be ___-dependent if it can exist in the database only when it is associated with another related
bridge
Another name for a composite entity is a ___ entity.
strong
Another word for existence-independent is ____.
domain
Attributes may share a ____.
logical data independence
Codd's Rule of ___ states: Application programs & 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.)
nonsubversion
Codd's Rule of ___ states: If the system supports low-level access to the data, users must not be allowed to bypass the integrity rules of the database.
redundancy
Controlled ___ makes a relational database work.
Julian
Date Attributes contain calendar dates stored in a special format known as the ___ date format.
row facts of interest to the end-user
End-user data is _____.
one
Ideally, an entity identifier is composed of ___ attributes.
existence
If an entity can exist apart from one or more related entities, it is said to be ____-independent.
synonym
In a database context, a(n) ___ indicates the use of different names to describe the same attribute.
underlining
In an ER diagram, primary keys are indicated by ___.
(min, max)
In the ERD, cardinality is indicated using the ____ notation.
hierarchical
In the ___ model, each parent can have many children, but each child has only one parent.
hierarchical
In the ___ model, the basic logical structure is represented as an upside-down tree.
network
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.
determines
In the context of a database table, the statement "A___B" indicates that if you know the value of attribute A, you can look up the value of attribute B.
maximum & minimum
Knowing the ___ number of entity occurrences is very helpful at the application software level.
semistructured
Most data you encounter is best classified as ____.
operational databases
Most decision-support data are based on historical data obtained from ___.
relational data model
MySQL is an example of a(n) _____.
hierarchical
One of the limitations of the ____ model is that there is a lack of standards.
XML/Hybrid data model
Oracle 11g is an example of a(n) _____.
conceptual
Some ___ database modeling concepts can be expressed only using the Chen notation.
simple
Some attributes are classified as _____.
many to many
Students and classes have a ___ relationship.
conceptual
The ERD represents the ___ database as viewed by the end user.
not null
The ___ constraint can be placed on a column to ensure that every row in the table has a value for that column.
object-oriented
The ___ data model is said to be a semantic data model.
object-oriented
The ___ data model uses the concept of inheritance.
system catalog
The ___ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.
external
The ___ model is the end users' view of the data environment.
entity relationship
The ___ model uses the term connectivity to label the relationship types.
1:1
The ___ relationship should be rare in any relation database design.
entity relationship
The ____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text.
DBMS
The ____ serves as the intermediary between the user and the database.
1:M
The ___relational type is the "relational model ideal."
functionally dependent on
The attribute B is ___ the attribute A if each value in column A determines one and only one value in column B.
=
The equijoin takes its name from the comparison operator ___used in the condition.
1960's
The hierarchical data model was developed in the ____.
1980's
The object oriented data model was developed in the ____.
1970's
The relational data model was developed in the ____.
logically, physically
The relational database model enables you to view data ___ rather than ____.
query result set
The response of the DBMS to a query is the ____.
domain
The set of possible values for an attribute is a ___.
select
To be considered minimally relational, the DBMS must support the key relational operators ____, PROJECT and JOIN.
unique
When you define a table's primary key, the DBMS automatically creates a(n) ___ index on the primary key column(s) you declared.
spreadsheet
Which of the following is an example of structured data?
serve as a communication tool between the users and designers
Which of the following is true of business rules?
semistructured
XML data is ____.
constraints
___ are important because they help to ensure data integrity.
constraints
___ are normally expressed in the form of rules.
union
___ combines all rows from two tables, excluding duplicate rows.
multivalued
____ attributes can have many values.
structured
____ data are the result of formatting to facilitate storage, use and generation of information.
unstructured
____ data exist in a format that does not lend itself to processing that yields information.
unstructured
____ data exist in the format in which they were collected.
Information
____ is used to reveal the meaning of data.
Metadata
____ provides a description of the data characteristics and the set of relationships that link the data found within the database.
project
____ yields a vertical subset of a table.
intersect
____ yields only the rows that appear in both tables.
select
____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.
a detailed description of organization operations
business rules are derived from ___.
