Database Systems Engineer Examination.pdf

October, 2005 VITEC

Database Systems Engineer

Examination (Afternoon, Part 2)

1. Examination Time-14:30-16:30 (120 minutes).
2.
Questions must be answered in accordance with the following:


Question Nos. Q1-Q2
Question Selection Select one of the two.

3. Mark your examinee information and test answers in accordance with the instructions
below.
(1) In the space provided on the answer sheet, write your examinee number. If this item is
not marked correctly, your test cannot be scored.
(2) In the space provided on the answer sheet, write your
date of birth
exactly as they are
printed on your examination admission card. It this item is not marked correctly, your
test cannot be scored.
(3) In the question selection column, circle the number of the question you select to
answer. If the question is not circled correctly, your test cannot be scored. If you circle
two numbers, only the first question will be graded.
(4) Write each answer in the space specified for that question.
(5) Write your answers clearly and neatly. Answers that are difficult to read will receive a
lower score.
4. After the test, you may take this question booklet home with you.
5. Observe

the rules
for describing conceptual data models, relation schemas, and relational
database tables provided at the beginning of the booklet.
Do not open the exam booklet until instructed to do so.
Inquiries about the exam questions will not be answered.

Company names and product names appearing in the test questions are trademarks or
registered trademarks of their respective companies. Note that the ® and ™ symbols are not
used within.
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Notation Used in the Questions

The notation for conceptual data models, relation schemas, and relational database table
structures is given below. This notation applies unless otherwise noted in the text of a
question.

1. Notation for Conceptual Data Models

Fig. 1 Notation for Entity Types and Relationships

(1) Entity types are indicated using rectangles.
(2) The entity type name is written inside the rectangle.
(3) The relationship between entity types is indicated using a line.
(4) For a “1-to-1 relationship,” neither end of the line is an arrow.
For a “1-to-many relationship,” one end of the line is an arrow.
For a “many-to-many relationship,” both ends of the line are arrows.


Fig. 2 Notation for Supertypes and Subtypes

(5) When representing supertypes and subtypes, lines are drawn between the supertype
and the subtypes, and a “
” is used at the branch point.
1 to 1
1 to many

Many to many
Entity type name
Entity type name
Entity type name
Entity type name
Entity type name
Entity type name
Supertype name
Subtype name Subtype name
ii

entity type name
attribute name 1, attribute name 2, ⋅⋅⋅
⋅⋅⋅, attribute name n
Fig. 3 Notation for the Attributes of Entity Types

(6) When representing the attributes of an entity type, the rectangle is divided into two
sections, upper and lower. The entity name is written in the upper section, while the
attribute names are listed in the lower section.
(7) When representing a primary key, a solid underline is used for the attribute name or
group of attribute names that make up the primary key.
(8) When representing a foreign key, a dotted underline is used for the attribute name or
group of attribute names that make up the foreign key. Note, however, that a dotted
underline is not used when some of the attributes that make up the primary key are
used to make up the foreign key.

2. Notation for Relation Schemas

relation name (attribute name 1, attribute name 2, ⋅⋅⋅, attribute name n)
Fig. 4 Notation for Relation Schemas

(1) A relation is represented by a relation name and a list of attribute names surrounded
by parentheses to the right of the relation name. This is called a relation schema.
(2) When representing a primary key, a solid underline is used for the attribute name or
group of attribute names that make up the primary key.
(3) When representing a foreign key, a dotted underline is used for the attribute name or
group of attribute names that make up the foreign key. Note, however, that a dotted
underline is not used when some of the attributes that make up the primary key are
used to make up the foreign key.

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3. Notation for Relational Database Table Structures

Table Name 1
Column name 1
Column name 2 Column name 3 Column name 4 Column name 5



Fig. 5 Notation for Table Structures, Primary Keys, Foreign Keys
and Reference Relationships

(1) A table name is entered followed underneath by the column names that make up the
table. Each column name is written inside a rectangle.
(2) When representing a primary key, a solid underline is used for the column name or
group of column names that make up the primary key.
(3) When representing a foreign key, a dotted underline is used for the column name or
group of column names that make up the foreign key. Note, however, that a dotted
underline is not used when some of the attributes that make up the primary key are
used to make up the foreign key.

(4) When representing a table to be referenced by the foreign key, a line is drawn either
above or below the column name or group of column names that make up the
foreign key. A rectangle is drawn at the end and the name of the table to be
referenced is entered inside. The end of the line on the foreign key side is an arrow.

Table name 2
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Q1. Read the following description of a distribution system, and then answer the
Subquestions 1 through 3.

Company Y manufactures and sells all kinds of office furniture including desks and
cabinets. These products are sold across the country through dealers such as
stationery stores, furniture stores and others. An issue is how to deal with large
variations in shipping frequency and volume. Work is therefore underway to improve
distribution operations and to build an efficient distribution system.

[Distribution Structure of Company Y]
The distribution structure of Company Y is shown in Figure 1. This kind of
distribution structure is generally called a “hub-and-spoke”. “Hub” refers to
shipment centers and transshipment centers, while “spoke” refers to the delivery of
products to destinations in the vicinity.



Fig. 1 Company Y’s Distribution Structure


The shipment centers and transshipment centers are collectively called “distribution
centers”. The thick arrow routes between distribution centers are “trunk routes”,
while the thin arrow routes between a distribution center and destinations are “branch

routes.” Often, a customer’s store or warehouse is specified as the destination, but
sometimes delivery is made directly to a relocated office or a newly opened office.

[Overview of Distribution Centers]
• A distribution center may have two functions: to “ship” products from inventory
and to “transfer” products from trucks that travel the trunk routes to trucks that
travel the branch routes.
• A shipment center has both shipping and transfer functions, while a
transshipment center has only a transfer function.
Legend

Shipment center
Transshipment center
Destination
Trunk route
Branch route
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• A given product is always stored in a designated shipment center.
• There are 6 shipment centers across the country. There are 1 or 2 transshipment
centers per district, a total of 60 throughout the country.

[Relationships between Order Received and Shipment and between Shipment and
Delivery]
• An “order received” refers to a single order from a customer. It is a unit to be
delivered to a specific destination on a specific day, and may contain multiple
products.
• A shipment is a received order’s subset consisting of products that are stored at
a shipment center.
• Products to be delivered to a destination are consolidated at the nearest
distribution center before their delivery.

• Figure 2 shows products example of relations between an order received and
shipments. In this example, five products ordered in AAA-city are shipped from
the BBB-city and CCC-city shipment centers and assembled into one shipment
at the DDD-city transshipment center.
Fig. 2 Example of Order Received and Shipment


[Product Delivery Patterns]
• Product delivery patterns at Company Y are shown in Figure 3. To simplify
matters, the figure shows only the movement of the products shipped from
shipment center A. The five patterns  through  in Fig. 3 are explained in
Table 1.
(Order received from AAA-city)
Sent by: AAA-city...
No. Product Qty
(Shipment at BBB-city)
Shipment center: BBB
No. Product Qty.
(Shipment at CCC-city)
Shipment center: CCC
No. Product Qty.
(Transfer at DDD-city and delivery)
Transshipment center:
DDD-city
No. Product Qty.
- 3 -
• There are three combinations of product movement patterns from shipment to
delivery to the customer, those being +, + and .

Table 1 Product Delivery Patterns
Shipping origin Shipping
destination
No.
Center Function
Route
 Shipment Shipment Shipment center Trunk
 Shipment Shipment
Transshipment
center
Trunk
 Shipment Shipment Destination Branch
 Shipment Transfer Destination Branch

Transshipment
center
Transfer Destination Branch

[Shipping Route Types and Area]
• Products are carried by truck.
• A section between origin and destination is called a shipping “route”. There are
two types: trunk and branch.
• For trunk routes, the number of days required for shipping (trunk route lead
time) is set in advance.
• A branch route is for delivering products to destination. Delivery scheduling is
organized in such a way that one or more areas can be covered in a day. The
“area” used here refers to a unit area defined by Company Y. There are about
200 areas across the country.

[Types of Services and of Trucks]

• Product delivery by a truck traveling a shipping route is referred to as a
“service”.
• Services come as either trunk services that run along a trunk route or branch
services that run along a branch route.
• The tonnage of trucks used for trunk services is 11t, 8t or 6t, while the tonnage
of trucks used for branch service is 4t or 2t.
• Each type of truck has a specific loading capacity, which includes some loss due
to unused space.



Fig. 3 Product Delivery
Patterns from Shipment
Center A
Shipment center A
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[Truck Assignment]
• Trucks are allocated for trunk and branch services either by advance assignment
or by additional assignment.
• Advance assignment is based on a stable volume of loads.
• Additional assignment is made on a daily basis for load volumes that do not fit
into advance assignments.
• A service number is issued in advance for trucks that are secured by advanced
assignment, whereas a new service number is issued whenever additional trucks
are needed.
• A load volume is calculated by multiplying the product quantity by the product
volume determined for each product.
• Products come in a wide variety of shapes and sizes; therefore product volume
is usually determined with some allowance provided.

[Daily Distribution Operations]
Figure 4 shows the flow of distribution operations. These operations are represented
by boxes, and the information that flows between them as well as the direction of the
flow are indicated by arrows. The box drawn with the dotted line is outside of the
distribution operations.



Fig. 4 Daily Distribution Operations Flow at Company Y


In daily distribution operations, shipment units are determined based on order
information provided by the sales department as a part of shipment scheduling
operations. All subsequent operations are conducted on the basis of the use of these
units. In shipment scheduling operations, shipment information is created for each
shipment unit. This information is forwarded to subsequent operations so that they
can be linked and coordinated. The shipment status contained in the shipment
information will be modified as subsequent operations are performed. This is
expressed as an attribute “shipment status” in the shipment information.

Order
received
Shipment
scheduling
Trunk
service truck
assignment
Branch
service truck
assignment

Shipment
Delivery
Transfer
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(Shipment scheduling)
• Order information is organized into units containing products which can be
shipped from a single shipment center. Shipment information is generated by
counting backwards the lead time required to deliver the products from the
established delivery time and date.
• Shipment information includes the originating distribution center, shipment
date, trunk route, transfer distribution center, transfer date, and branch route.
(Trunk service truck assignment)
• The shipment load for each trunk route is calculated from the shipment
information. If necessary, additional trucks are allocated.
• The trunk route service to be used in respect of each shipment information is
decided, and the service number of that shipment is recorded.
• At this stage, the shipment status is listed as “trunk service truck assigned”.
• Products that make up a shipment are handled as one unit and not divided up
into multiple delivery service.
(Branch service truck assignment)
• The shipping load for each branch route is calculated on the basis of the
shipment information. If necessary, additional trucks are allocated.
• The branch route to be used in respect of the shipment information is decided,
and the service number of that shipment is recorded.
• At this stage, the shipment status is listed as “branch service truck assigned”.
• To the greatest extent possible, the shipment for a single order is grouped and
assigned to a single branch service, but the shipment may be split into several
trucks if it exceeds the maximum load of a single truck.
(Shipment)
• Products are shipped as determined by the trunk service truck assignment or

branch service truck assignment.
• If delivery is to be made directly to a destination by branch service without
using trunk service, a delivery slip is printed for that specific order before the
products are shipped.
• When the products are shipped, the shipping date is recorded in the shipment
information.
• At this stage, the shipment status is listed as “shipped”.
(Transfer)
• Whenever a service truck arrives, the individual packages are divided into
respective branch service as instructed in the shipment information.
• A delivery slip is printed for each specific order before the branch service trucks
depart.
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• The individual branch service trucks depart as soon as they are loaded with
same-day-delivery packages and their respective delivery slips distributed
accordingly.
• When the branch service trucks depart, the transfer date is recorded in the
shipment information.
• At this stage, the shipment status is listed as “transferred”.
(Delivery)
• The delivery slip is presented to the customer upon delivery at the destination.
The customer acknowledges delivery by signing the delivery slip copy.
• After a branch service truck returns to the distribution center, the delivery date
written on the delivery slip copy is recorded in the shipment information.
• At this stage, the shipping status is listed as “delivered.”
(Coordination of loading space)
At the shipping center, space is secured in the warehouse by product. Once the
products are taken from the warehouse and marshaled, they are loaded onto the
trucks. The space allocated for marshalling looses its efficiency whenever sales
trends change. Therefore, marshalling space assignment is reviewed periodically,

using following indicators calculated for each shipping center on a monthly basis.
• Number of shipments per product
• Average quantity per shipment per product

(Conceptual data model of distribution operations)
Fig. 5 shows a conceptual data model of the distribution operations, and Fig. 6 shows
the list of the relational schemas in the distribution operations. (Both are partially
incomplete.)



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Distribution
center
Shipment center
Branch route Trunk route
Truck type
Shipping route Product
Truck assignment
Area
Order received
Shipment
Shipment detailOrder detail

Fig. 5 Conceptual Data Model of Distribution Operations