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Explain the pragmatic reason for using surrogate keys.

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Primary keys are commonly included in in...

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After a 1:1 relationship has been created between two tables in Microsoft Access,the Relationship Type of One-To-One appears ________.


A) in the Relationship Type property of the primary key column in table Design View
B) in the Relationship Type property of the foreign key column in table Design View
C) in the table object in the Relationships window
D) in the Show Table dialog box
E) in the Edit Relationships dialog box

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Which of the following is true when representing a 1:1 binary relationship using the relational model?


A) The key of the entity with the highest minimum cardinality must be placed in the other entity as a foreign key.
B) The key of each entity must be placed in the other as a foreign key.
C) The key of either entity is placed in the other as a foreign key.
D) The key of the entity with the most attributes must be placed in the other entity as a foreign key.
E) Both entities must have the same primary key.

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To represent a many-to-many relationship in the relational model,a(n)________ table is used.

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As far as Microsoft Access is concerned,there are no N:M relationships.

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True

In many-to-many relationships in a relational database design,________.


A) the intersection table is ID-dependent on one of the parents
B) the intersection table is ID-dependent on both of the parents
C) the minimum cardinality from the intersection table to the parents is always M
D) Both A and B
E) Both B and C

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To represent a M:N relationship in the relational model,an intersection table is created to represent the relationship itself.

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True

The first step in representing entities using the relational model is to determine which identifier will be used as the key.

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What is an association relationship,and how does it differ from an N:M relationship?

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An association relationship is very simi...

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Which of the following is not true about representing subtypes in a relational database design?


A) One table is created for the supertype and one for each subtype.
B) All of the attributes of the supertype are added to the subtype relations.
C) The key of the supertype is made the key of the subtypes.
D) A subtype and its supertype are representations of the same underlying table.
E) An instance of the supertype may be related to one instance each of several subtypes.

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All recursive relationships are 1:1.

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A(n)________ is a relationship among entities of the same class.

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recursive ...

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In a relational database design,all relationships are expressed by ________.


A) creating a primary key
B) creating a foreign key
C) creating a supertype
D) creating a subtype
E) creating a line between entities

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An entity needs to be examined according to normalization criteria before creating a table from it in the relational database design.

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To create a 1:1 relationship in Microsoft Access,the Indexed property of the foreign key column must be set to Yes (No Duplicates).

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By default,the identifier of the entity becomes the foreign key of the corresponding table.

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What relationship pattern is illustrated in the following schema? PRODUCT (ProductID,Description) SUPPLIER (SupplierID,ContactName,PhoneNumber) PRODUCT_SUPPLIER (ProductID,SupplierID,Cost) ProductID in PRODUCT_SUPPLIER must exist in ProductID in PRODUCT SupplierID in PRODUCT_SUPPLIER must exist in SupplierID in PRODUCT


A) Association relationship
B) Intersection relationship
C) Recursive relationship
D) Strong entity relationship
E) Supertype/subtype relationship

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In the relational model,many-to-many relationships cannot be directly represented by relations the way 1:1 and 1:N relationships can.

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True

For a(n)________ weak entity,it is necessary to add the key of the parent entity to the weak entity's relation so that this added attribute becomes part of the weak entity's key.

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One of the important properties of a column is whether or not it is ________.


A) found in more than one entity
B) required
C) character or numeric
D) subject to normalization
E) subject to denormalization

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