Database Management Test 2 Q&A

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

in the Edit Relationships dialog box

! 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

Association relationship

! Which of the following is not true of recursive relationships?

The rows of a single table can play two different roles.

! A dashed line between entities indicates _________. 

a nonidentifying relationship

! The number of entity classes involved in a relationship is known as the relationship’s _________.

degree

! Which of the following statements is not true about creating data models when facts are missing.

The data model process stops until all the necessary facts are obtained. 

! The first steps in transforming an extended E-R model into a relational database design is to ___________.

create a table for each entity

! A use case can be used to perform which of the following tasks?

Validate the data model

! Microsoft Access is a good tool for creating mock-ups of forms and reports because _________.

Access wizards make it easy to create the forms and reports.

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

All of the attributes of the supertype are added to the subtype relations.

! In crow’s foot style E-R diagrams, a circle across the relationship line near an entity indicates __________. 

a minimum cardinality of optional

! Which of the following activities is not performed during the implementation phase of developing a database system?

Transforming the data model into a database design

! Which of the following is true about representing a weak entity with the relational model? 

If the weak entity is ID-dependent, the key of the parent entity must be part of the key of the weak entity. 

! What relationship pattern is illustrated in the following schema?

VEHICLE (VehicleID, Cost)

CAR (VehicleID, NumberOfSeats)

TRUCK (VechicleID, CargoCapacity)

VehicleID in CAR must exist in VehicleID in VEHICLE

VehicleID in TRUCK must exist in VehicleID in VEHICLE

Supertype/subtype relationship

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

The key of either entity is placed in the other as a foreign key.

! Microsoft Access can be used to build a prototype database, which allows users __________.

to validate the data model by demonstrating the consequences of data modeling decisions

! The identifier of the entity becomes the __________ of the corresponding table.

primary key

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

the keys of both tables are joined into a composite key

! Whether or not an instance of one entity class must participate in a relationship with another entity class is indicated by the _______.

minimum cardinality

! Which of the following statements is not true about intersection tables?

It is a parent table.

! Given only the following excerpt of an E-R model:\

A diagram of the E R model shows entity A and entity B are connected by symbols representing zero or many and one (and only one) respectively.

Which of the following is known to be true?

Many instances of ENTITY A may be related to one instance of ENTITY B. 

! Given only the following excerpt of an E-R model:\

A diagram of the E R model shows entity A and entity B are connected by symbols representing zero or many and one (and only one) respectively. 

If one instance of ENTITY B must be related to one and only one instance of ENTITY A, and one instance of ENTITY A may be related to many instances of ENTITY B, which of the following should be written on the end of the relationship line next to ENTITY B in the figure above?

A diagram of the ER model shows entity B connected by symbols representing one or many. 

! An ID-dependent entity is _________.

an entity in which the identifier of the entity includes the identifier of another entity.

! Which of the following would be a reason to denormalize a relation?

Improve performance

! Which of the following is the correct technique for representing a 1:N relationship in the relational model?

The key of the entity on the one side is placed into the relation for the entity on the many side.

! The Microsoft Access form editor is a(n) _________.

banded form editor

! Which of the following is not a basic element of the E-R Model?

Use cases

! To create a 1:1 relationship between two tables in Microsoft Access ___________.

the Indexed property of the foreign key column must be set to Yes (No Duplicates)

! In crow’s foot style E-R diagrams, a crow’s foot mark on the relationship line near an entity indicates __________.

a maximum cardinality of many

! In relational database design, ID-dependent entities are used to ___________.

represent N:M relationships

! Which of the following is true about identifiers of entities?

The value of an identifier may identify a set of entity instances.

! Microsoft Access does not create N:M relationships because __________.

Microsoft Access creates databases based on database designs instead of data models.

! Which of the following is the correct technique for representing a N:M relationship using the relational model?

An intersection relation is created, and the keys of both parent entities are placed as a composite primary key in the intersection relation. 

! Given the tables

PRODUCT (ProductID, Description, Cost)

SUPPLIER (SupplierID, ContactName, PhoneNumber)

as shown in the figure below, which of the following would represent the correct placement of foreign keys?

A diagram of an ER model showing the relationship between product and supplier (with a slight difference in the relationship). The ProductID description, and cost are indicated in Product while SupplierID, contact name, and phone number are indicated in Supplier. These two entities are connected by symbols representing zero or many and one or many respectively. PK indicated near ProductID and SupplierID. 

PRODUCT (ProductID, Description, Cost)

SUPPLIER (SupplierID, ContactName, PhoneNumber)

PRODUCT_SUPPLIER (ProductID, SupplierID)

! Which of the following would not be contained in a use case?

A prototype of the system performing a given task.

! What relationship pattern is illustrated in the following schema?

EMPLOYEE (EmployeeID, OfficePhone, Manager)

Manager in EMPLOYEE must exist in EmployeeID in EMPLOYEE

Recursive Relationship

! As far as Microsoft Access is concerned, there are no _________.

N:M relationships

! Which of the following is not a source for user requirements during the requirements analysis stage of developing a database system?

Referential integrity constraints

! Given the tables

PRODUCT (ProductID, Description, Cost)

SUPPLIER (SupplierID, ContactName, PhoneNumber)

as shown in the figure below, which of the following would represent the correct placement of foreign keys?

A diagram of an ER model showing the relationship between product and supplier. The ProductID, description, and cost are indicated in Product while SupplierID, contact name, and phone number in Supplier. These two entities are connected by symbols representing zero or many and one (and only one) respectively. PK indicated and near ProductID and SupplierID.

PRODUCT (ProductID, Description, Cost, SupplierID)

SUPPLIER (SupplierID, ContactName, PhoneNumber)

! In terms of normalization, what do the letters BCNF stand for?

Boyce-Codd Normal Form