MIS 375 EXAM 2 QUESTIONS AND ANSWERS
What is the purpose of developing an identifier for an entity? - Answer -An identifier
helps uniquely identify data and create ways to be able to differentiate different lines of
data.
What type of high‐level business rule can be stated by an ERD? Give two examples. -
Answer -How two entities relate and if information can actually be determined from the
Data.
Define what is meant by an entity in a data model. How should an entity be named?
What information about an entity should be stored in the CASE repository? - Answer -
the basic building block for a data model. It is a person, place, event, or thing about
which data is collected
Entities should be named with a word that describes the entire table. This way, anyone
going into the database knows what exactly is in the table.
The information about an entity that should be stored in the case repository is the data
flow from the entity because the data flow shows the process that the data has gone
through.
Define what is meant by an attribute in a data model. How should an attribute be
named? What information about an attribute should be stored in the CASE repository? -
Answer -some type of information that is captured about an entity. This means that
attributes in the data model show the information inside the tables.
An attribute should be named by what it is. Use of short words is good and making sure
to say if the attribute is an ID or not.
All the information about an attribute should be stored in the case repository because
that is where this information is stored.
Define what is meant by a relationship in a data model. How should a relationship be
named? What information about a relationship should be stored in the CASE
repository? - Answer -A relationship shows how two entity's connect and share a
certain point of data.
A relationship should be named by what the connection is representing. When two
attributes are next to each other, the name reads from left to right and when two
attributes are one on top of the other, they read top to bottom.
The only information that should be stored in the repository is which attributes are
connected in each table.
A team of developers is considering including "warehouse" as an entity in its data
model. The company for whom they are developing the system has just one warehouse
location. Should "warehouse" be included? Why or why not? - Answer -Warehouse
should not be included considering there is only one warehouse for the company. The
only time it would make sense to have a warehouse table would be when more than
one warehouse is in use. This way, it would be easier to differentiate
, What is meant by a concatenated identifier? - Answer -A concatenated identifier means
that more than one attribute is an identifier showing that a conclusion for the data could
not be made with only one attribute as the identifier
Describe, in terms a businessperson could understand, what are meant by the
cardinality and modality of a relationship between two entities. - Answer -The
cardinality of two entities shows the relationship between two tables. Let's say it is the
tables customer and order. With these two tables, a customer can have no orders, one
order, or many orders. An order can be made by only one customer though.
What are metadata? Why are they important to system developers? - Answer -
Metadata is data about data. This data helps inform the user on what an entity, attribute,
or relationship is defined as. Metadata is important to system developers because it
creates a data dictionary for users to be able to understand what data they need to pull
and even though something looks useful, it may not be saying exactly what the
developer needs.
What is an independent entity? What is a dependent entity? How are the two types of
entities differentiated on the data model? - Answer -An independent entity is an entity
that can exist without the help of another entity. Attributes from other entities were not
needed to uniquely identify instances of these entities.
A dependent entity is when an identifier consists of at least one attribute from the parent
entity. This way an entity cannot be fully unique because it is dependent on other
entities to be unique.
These two types of relationships are differentiated in the data model because it is
important to know which tables are dependent on others while other tables do not rely
on others to create information.
Explain the distinction between identifying and non identifying relationships. - Answer -
Non-identifying relationships are when a relationship includes an independent child
entity. parent entity attributes are not needed as part of the child entity's identifier.
Identifying relationships are when relationships have a dependent child entity. This is
when parent entity attributes are needed as part of the child entity's identifier.
What is the purpose of an intersection entity? How do you know whether one is needed
in an ERD? - Answer -An intersection entity helps reduce information on tables and
lower the amount of data points per table. These are typically found on a many to many
relationship table because data can be duplicated on both ends. These are needed
when normalizing a database in order for data to be concise and stored easily.
Describe the three‐step process of creating an intersection entity. - Answer -Step 1:
Remove the M:N relationship line and insert a new entity in between the two existing
ones.
What is the purpose of developing an identifier for an entity? - Answer -An identifier
helps uniquely identify data and create ways to be able to differentiate different lines of
data.
What type of high‐level business rule can be stated by an ERD? Give two examples. -
Answer -How two entities relate and if information can actually be determined from the
Data.
Define what is meant by an entity in a data model. How should an entity be named?
What information about an entity should be stored in the CASE repository? - Answer -
the basic building block for a data model. It is a person, place, event, or thing about
which data is collected
Entities should be named with a word that describes the entire table. This way, anyone
going into the database knows what exactly is in the table.
The information about an entity that should be stored in the case repository is the data
flow from the entity because the data flow shows the process that the data has gone
through.
Define what is meant by an attribute in a data model. How should an attribute be
named? What information about an attribute should be stored in the CASE repository? -
Answer -some type of information that is captured about an entity. This means that
attributes in the data model show the information inside the tables.
An attribute should be named by what it is. Use of short words is good and making sure
to say if the attribute is an ID or not.
All the information about an attribute should be stored in the case repository because
that is where this information is stored.
Define what is meant by a relationship in a data model. How should a relationship be
named? What information about a relationship should be stored in the CASE
repository? - Answer -A relationship shows how two entity's connect and share a
certain point of data.
A relationship should be named by what the connection is representing. When two
attributes are next to each other, the name reads from left to right and when two
attributes are one on top of the other, they read top to bottom.
The only information that should be stored in the repository is which attributes are
connected in each table.
A team of developers is considering including "warehouse" as an entity in its data
model. The company for whom they are developing the system has just one warehouse
location. Should "warehouse" be included? Why or why not? - Answer -Warehouse
should not be included considering there is only one warehouse for the company. The
only time it would make sense to have a warehouse table would be when more than
one warehouse is in use. This way, it would be easier to differentiate
, What is meant by a concatenated identifier? - Answer -A concatenated identifier means
that more than one attribute is an identifier showing that a conclusion for the data could
not be made with only one attribute as the identifier
Describe, in terms a businessperson could understand, what are meant by the
cardinality and modality of a relationship between two entities. - Answer -The
cardinality of two entities shows the relationship between two tables. Let's say it is the
tables customer and order. With these two tables, a customer can have no orders, one
order, or many orders. An order can be made by only one customer though.
What are metadata? Why are they important to system developers? - Answer -
Metadata is data about data. This data helps inform the user on what an entity, attribute,
or relationship is defined as. Metadata is important to system developers because it
creates a data dictionary for users to be able to understand what data they need to pull
and even though something looks useful, it may not be saying exactly what the
developer needs.
What is an independent entity? What is a dependent entity? How are the two types of
entities differentiated on the data model? - Answer -An independent entity is an entity
that can exist without the help of another entity. Attributes from other entities were not
needed to uniquely identify instances of these entities.
A dependent entity is when an identifier consists of at least one attribute from the parent
entity. This way an entity cannot be fully unique because it is dependent on other
entities to be unique.
These two types of relationships are differentiated in the data model because it is
important to know which tables are dependent on others while other tables do not rely
on others to create information.
Explain the distinction between identifying and non identifying relationships. - Answer -
Non-identifying relationships are when a relationship includes an independent child
entity. parent entity attributes are not needed as part of the child entity's identifier.
Identifying relationships are when relationships have a dependent child entity. This is
when parent entity attributes are needed as part of the child entity's identifier.
What is the purpose of an intersection entity? How do you know whether one is needed
in an ERD? - Answer -An intersection entity helps reduce information on tables and
lower the amount of data points per table. These are typically found on a many to many
relationship table because data can be duplicated on both ends. These are needed
when normalizing a database in order for data to be concise and stored easily.
Describe the three‐step process of creating an intersection entity. - Answer -Step 1:
Remove the M:N relationship line and insert a new entity in between the two existing
ones.
