Semester 1 Mid Term Exam Covers Sections 1 CORRECTIE 1

7/31/2019 Semester 1 Mid Term Exam Covers Sections 1 CORRECTIE 1

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Semester 1 Mid Term Exam covers Sections 1-10 of Database

Design.


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(Beantwoord alle vragen in deze sectie.)

Intersection Entities are at the Master end in the relationships between it and the original entities. So the originalentities are details or children of the newly created intersection entity. True or False?

Markeren voor nakijken(1) Punten

Waar


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Intersection Entities often have the relationships participating in the UID, so the relationships are often barred.True or False?

Markeren voor nakijken

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What do you call the entity created when you resolve a M:M relationship?



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A non-transferable relationship means the detail can be changed to point to a new master. True or False?



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How do you include a relationship as part of the UID for an entity? Markeren voor nakijken(1) Punten


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If two entities have two relationships between them, these relationships can be either _____________ or_____________ ?


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What uncommon relationship is described by the statements: "Each DNA SAMPLE may be taken from one andonly one PERSON and each PERSON may provide one and only one DNA SAMPLE"



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Which of the following pairs of entities is most likely to be modeled as a M:M relationship?



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A supertype can only have two subtypes and no more. True or False?



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All ER diagrams must have one of each of the following: (Choose two) Markeren voor nakijken(1) Punten

(Kies alle goede antwoorden.)


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The "Other" subtype is mandatory. True or False?


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All instances of the supertype must be an instance of one of the subtypes. True or False?


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A new system would have a mixture of both Procedural and Structural Business Rules as part of thedocumentation of that new system. True or False?



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Arcs are used to visually represent _________ between two or more relationships in an ERD.



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An arc can also be modeled as Supertype and Subtypes. True or False?



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Which of the following is NOT a relationship type?



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No parts of an UID are mandatory. True or False? Markeren voor nakijken(1) Punten


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Which of the following would best be represented by an arc?



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Which of the following scenarios should be modeled so that historical data is kept? (Choose two)




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Historical data must never be kept. True or False?




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A relationship can be both Recursive and Hierachal at the same time. True or False?



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Which of the following would be good as a Unique Identifier for its Entity? (Choose Three)




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Which of the following entities most likely contains valid attributes? (Choose two)



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An entity can have many Unique Identifiers. True or False?


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The entity/relationship model is created before the physical database design model? True or False?



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A/an _________ is a picture of all the information that will form the basis for the finished system.



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Which of the following are examples of ENTITY: Instance. (Choose Two)




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Entity Relationship modeling is dependent on the hardware or software used for implementation, so you will need

to change your ERD if you decide to change Hardware Vendor. True or False? Markeren voor nakijken(1) Punten


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An ERD is an example of a Physical Model. True or False?



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Entity Boxes are drawn with 90 degree angles, also known as Hard Boxes. True or False?


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Matrix Diagrams are developed BEFORE the ERD. True or False?



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Which of the following are valid relationship degrees? (Choose two)




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Relationship Degree/Cardinality is important. True or False?



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There is no point in trying to group your entities together on your diagram according to volume. Making adiagram pretty is a waste of time. True or False?



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There are formal rules for how to draw ERD's, even though they are only guidelines, you should always try to

follow them. True or False?Markeren voor nakijken

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All datamodels must be transformed from specific to generic. True or False?



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A datamodel containing generic modeling techniques must not be mixed in with non-generic models. The genericentities MUST be drawn on a diagram of their own. True or False?



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You are doing a data model for a computer sales company, where the price of postage is dependent on what dayof the week goods are shipped. So shipping is more expensive if the customer wants a delivery to take place on a

Saturday or Sunday. What would be the best way to model this?Markeren voor nakijken

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All systems must include functionality to provide logging or journaling in conceptual data models. True or False?


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All systems must have an entity called WEEK with a holiday attribute, so you know when to give your employeesa holiday. True or False?


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If a system includes the concept of time and it stores Start Dates, then End Dates becomes Mandatory. For eachStart Date attribute you create, you MUST create an End Date attribute and it must be mandatory. True or False?



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When you add the concept of time to your data model, your model becomes more complex. True or False?



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No commercial database systems in the world will accept tables that are not on 3rd Normal Form. True or False?



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Until all attributes are single-valued, the database model is said to be:



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Normalizing an Entity to 1st Normal Form is done by removing repeated or redundant attributes. True or False?


Would it be a good idea to model age as an attribute of STUDENT?


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Any Non-UID must be dependant on the entire UID. True or False?



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All entities must be given a new artificial UID. True or False?



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A unique identifier must be made up of more than one attribute. True or False?


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Semester 1 Mid Term Exam Covers Sections 1 CORRECTIE 1