Database Systems Engineer Examination.pdf

October, 2005 VITEC
Database Systems Engineer Examination (Morning)

1. Examination Time-9:00-10:30 (90 minutes).

2. Questions must be answered in accordance with the following:

Question Nos. Q1-Q50
Question Selection All questions are compulsory

3. Mark your examinee information and test answers in accordance with the instructions below.
(1) Use an HB black pencil. If you need to change an answer, fully erase the undesired
mark with a rubber eraser until no mark remains. Remove rubber bits on the paper.
(2) Answer sheets are processed through an optical reader. Mark your answers according
to the answer sheet marking method given in (5) below.
(3) Fill in and mark the test number in the test number area. If an answer is not marked
correctly, or is marked differently than explained in (5), your test cannot be scored.
(4) In the Date of Birth area, fill in your Date of Birth exactly as printed on your test form.
If this item is not marked correctly, your test cannot be scored.
(5) Mark only one answer for each question, as shown in the example below.

Example: In what month is the Spring Information Processing Engineer Exam held?

a) February b) March c) April d) May

Since the correct answer is “c” (April), mark your answer sheet as follows:

[Sample Reply]

4. After you complete and turn in your exam, you can take this question booklet home
with you.





Do not open the exam booklet until instructed to do so.
Inquiries about the exam questions will not be answered.
a) b)
d)

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.
- 1 -

Q1
Which system attempts to speed up data transfer to an auxiliary storage device equipped with
the channel control system of a general-purpose computer, by continually sending data without
waiting for a confirmation signal?

a) Serial system b) Streaming system
c) Parallel system d) Handshake system


Q2
Which of the following is a von Neumann bottleneck (a factor that prevents performance
improvement with a computer that sequentially fetches and executes program instructions in
the CPU)?

a) Main memory capacity
b) Data transfer capacity between an internal device (processor and main memory) and
an I/O device
c) Data transfer capacity between a processor and the main memory
d) Processor performance


Q3
Which of the following is a correct statement concerning virtual storage systems?

a) An LRU algorithm is a page-replacing algorithm that replaces the page for which the
the longest time has elapsed since it was last used.
b) To convert an address by indexing requires a page table of all pages in the main

memory.
c) When a page fault occurs, garbage collection is required.
d) Fragmentation occurs when many small areas of available memory are created
during repeated paging.










- 2 -

Q4
Which of the following is a correct statement concerning OS scheduling methods?

a) In the processing time-sequenced method, higher priority is given to the job that has
already consumed a larger amount of CPU time.
b) Response time, for jobs requiring particularly short processing time, is much shorter
in the arrival-sequenced method in comparison with the round robin method.
c) In the priority-sequenced method, the response time of some jobs can be extremely
long.
d) The shorter the CPU time (time quantum) allocated to a job in the round robin
method, the closer the method is to the arrival-sequenced method.


Q5

Which of the following is a correct statement in regard to a preemptive system in OS process
control?

a) Each process can manage system resources autonomously, so the preemptive system
is well-suited to multi-programming.
b) The preemptive system has less context switching overhead than the non-preemptive
system.
c) In the preemptive system, certain processes monopolize the processor more
frequently than in the non-preemptive system.
d) Realizing a preemptive system requires a mechanism whereby the OS can forcefully
switch and execute processes.


Q6
Which of the following systems offers the best results in introducing a three-tier client-server
architecture?

a) A system with a small number of application services and classes
b) A system where correction and addition of applications are frequent
c) A system in which all applications are written in the same language
d) A system with a comparatively small number of transactions


Q7
- 3 -

A device provides services at a rate of 5 sec per transaction on the average. What is the least
number of devices needed to bring device usage rate below 0.5 sec, even when the average
arrival is 20 transactions per minute?

a) 2 b) 3 c) 4 d) 5


Q8.
A system sends data from a server to a magnetic disk device over a LAN at a data transfer rate
of 10 Mbps. The table below gives the measured transfer speed of the server and the measured
reception speed of the client for differing numbers of clients to which the server simultaneously
sends data. From these results, it can be seen that server transfer speed does not increase over
300 Kbps when there are 2 or more clients. Which of the following is the most likely cause of
this? In all of these measurements, the server and all of the clients have sufficient CPU
performance and memory capacity.

Data transfer rate (Kbps)
Measurement
case
Number of
clients
Average for server
(Transfer)
Average per client
(Reception)
Case 1 1 150 150
Case 2 2 300 150
Case 3 3 300 100

a) Insufficient data transfer capacity of the LAN itself
b) Insufficient capacity of the client’s LAN connection interface mechanism
c) Insufficient capacity of the client’s magnetic disk device
d) Insufficient capacity of the server’s LAN connection interface mechanism

Q9
If the performance of a single CPU is 1, then the performance P of a multiprocessor containing
n these CPUs is expressed as:

In this formula, a is a constant which expresses the overhead. For example, if a = 0.1 and n = 4,
then P
3, so the performance of a multiprocessor consisting of 4 CPUs is approximately 3.
The multiprocessor performance expressed in this equation has an upper limit. It will not
increase beyond a certain value no matter how large a number n may be. What is this value if a
= 0.1?

a) 5 b) 10 c) 15 d) 20


Q10
- 4 -

Which of the following correctly expresses the MTBF and MTTR of the system in the work
model diagram below? Here, t
i
is the system running time and r
i
is the system repair time (i = 1,
2, …, n).



MTBF MTTR
a)

b)


c)


d)




Q11
Which of the following statements correctly describes a technology used to increase the
reliability of a computer system?

a) “Failsafe” is a technology that reduces failure by increasing the reliability of
individual components.
b) “Failsoft” is a technology for handling system faults caused by software.
c) “Fault avoidance” is a technology that enables operations to continue even if a failure
occurs in a component.
d) “Fault tolerance” is a technology, whereby critical parts which form a system are
installed redundantly, to cope with the occurrences of failures.

Q12
Running
Running Running
Failure Failure Failure
Repair Repair
Repair
Running
- 5 -

Which of the following statements correctly describes data mining?

a) Its primary objective is the analysis of time-series data which do not involve update
processes, created separately from the core operations database.
b) It analyzes customized data that are extracted according to the analyzer’s objectives,
such as personal data, departmental data, and summary data.
c) It performs multidimensional analysis through interactive operations such as slicing,
dicing, and drilling down in order to support decision-making.
d) It creates theories, such as customer purchasing behaviors, from large amounts of
stored data using neural networks, statistical analysis, and other techniques.


Q13
Which of the following is the correct expression of the recall ratio and precision ratio used as
measures in evaluating information retrieval systems, such as document retrieval systems and
data retrieval systems? Here,
A

,
B
and
C
indicate the following.
A
: The number of data cases amongst all accumulated data that are suitable to the inquiry
B
: The number of data cases amongst retrieved data that are suitable to the inquiry
C
: The number of data cases retrieved

Recall ratio Precision ratio
a)
A

/

B

B

/

C

b)
B

/

A

B

/

C

c)
B

/

A

C

/

B

d)
C

/

B

A

/

B



Q14
Which of the following is a correct statement concerning “frames” as a method for expression
of knowledge?

a) Its format consists of expression of concepts as nodes, and relations or characteristics
as directional arcs.
b) It has an IF-THEN format to express conditions and behavior.
c) Its format comes from a correspondence list of slot-to-slot values.
d) Its format consists of proposition logic and predicate logic.



Q15
Which of the following correctly defines a repository in software development?
- 6 -


a) It is a database of software components provided to support development.
b) It is a database that centrally manages design information and program information
in software development and maintenance.
c) It is a database for storing software development tools and data models.
d) It is a database for storing source program analysis software and analysis results for
reverse engineering.

Q16
Which of the following is a correct statement in regard to prototyping?

a) It is more suitable for batch systems than GUI-based interactive systems.
b) Effectiveness can be increased by repeatedly remaking the prototype.
c) It assumes there are frequent requirement specification changes, so it cannot be used
in the waterfall model.
d) It is not suited for the development of systems with a long life cycle or for packages
to be used by many people.


Q17
Which of the following is a correct statement concerning inheritance in object orientation?

a) When a subclass is defined under a given class, the data structures and procedures
defined in the higher class can be inherited and used in the subclass.
b) Data structures and values determining an object’s characteristics are hidden and
direct access from outside the object is prohibited.
c) Even if an object’s data structure or processing method is changed, impact to the
outside can be avoided, allowing the object’s independence to be improved.
d) It expresses objects having identical data structures and identical procedures all
together.





Q18

Which of the following is a correct statement in regard to black box tests?
- 7 -


a) Test case coverage is used as a criterion for creating test data.
b) Even if the tested program contains redundant code, it cannot be detected.
c) A black box test focuses on a program’s internal structure and verifies whether the
required parts have been executed.
d) Test data increases significantly as the numbers of branch instructions and modules
increase.


Q19
There is a database in which data additions, changes, and deletions occur at a certain low
frequency. The interval between backups has been increased to twice the current level for
backing the database onto magnetic tape. Which of the following is a correct statement with
respect to the database operations?

a) The average recovery time from journal information will increase by a factor of
approximately 2.
b) The database capacity will increase by a factor of approximately 2.
c) The number of magnetic tapes required for a single backup will decrease by
approximately one-half.
d) The average backup execution time will increase by a factor of approximately 2.


Q20
Which of the following correctly describes an ANSI/SPARC schema of a three-layer structure
that defines all of the real world data required in data processing and a data structure that does
not depend on a special application program?

a) Conceptual schema b) External schema
c) Subschema d) Internal schema









Q21
Which of the following statements correctly describes a conceptual data model?