Oracle Sample Question - Contradiction with Cade's study guide
posted 6 years ago
2) Your organization has a legacy thick-client application. The issue is that the presentation and business logic are currently coupled. A change in presentation logic requires a change in business logic. A suggestion is to re-factor this into a three-tier application and separate the business logic from the presentation logic.
What non-functional requirement would you improve by separating the presentation layer from the business layers?
a) Security
b) Response Time
c) Manageability
d) Maintainability (*)
e) Performance
REFERENCE:
Practical Software Estimation: (M. A. Parthasarathy)
Option D is correct.
Option A is incorrect because securing a one-tier application is generally easier than securing a three-tier application. With a three-tier you need to secure the web server, application server, and database.
Option C is incorrect because manageability of one-tier application is generally easier than tree-tier application. With a three-tier you need to manage the health the web server, application server, and database.
Options B, E are incorrect because performance and response time of a one-tier system should be better than a three-tier. With a three-tier application the request/response cycle includes a web server, application server, and database.
I may be completely offtrack here as they talk about one-tier application rather than two-tier, but...
If you refer to page 31 and 32 of Mark Cade's Study guide (in particular, advantages and disadvantages of 2, 3 and n-tier), it basically says that (quote):
1) Two-tier (disadvantage): "Manageability is problematic, as it becomes almost impossible to monitor all the PCs that are running the client code." <=== this contradicts reasoning of Option C above
2) Three-tier (advantage): "Performance could be an advantage or disadvantage. Primarily, it is an advantage, as you can spread out the processing over many servers, but it can become a disadvantage if you have to transfer large amounts of data between the servers." <=== If we weren't transferring too much data, would it be an advantage or disadvantage, given reasoning for Option B, E above?
3) Three-tier (advantage): "Separating the tiers allows for more points to secure the system" <=== My understanding of this is, given that there are more points to secure it will be more secure (because you can contain the threat in that tier), but harder to secure (more work involved). Is this correct?
Any clarification would be greatly appreciated.
Thanks,
Marcelo
What non-functional requirement would you improve by separating the presentation layer from the business layers?
a) Security
b) Response Time
c) Manageability
d) Maintainability (*)
e) Performance
REFERENCE:
Practical Software Estimation: (M. A. Parthasarathy)
Option D is correct.
Option A is incorrect because securing a one-tier application is generally easier than securing a three-tier application. With a three-tier you need to secure the web server, application server, and database.
Option C is incorrect because manageability of one-tier application is generally easier than tree-tier application. With a three-tier you need to manage the health the web server, application server, and database.
Options B, E are incorrect because performance and response time of a one-tier system should be better than a three-tier. With a three-tier application the request/response cycle includes a web server, application server, and database.
I may be completely offtrack here as they talk about one-tier application rather than two-tier, but...
If you refer to page 31 and 32 of Mark Cade's Study guide (in particular, advantages and disadvantages of 2, 3 and n-tier), it basically says that (quote):
1) Two-tier (disadvantage): "Manageability is problematic, as it becomes almost impossible to monitor all the PCs that are running the client code." <=== this contradicts reasoning of Option C above
2) Three-tier (advantage): "Performance could be an advantage or disadvantage. Primarily, it is an advantage, as you can spread out the processing over many servers, but it can become a disadvantage if you have to transfer large amounts of data between the servers." <=== If we weren't transferring too much data, would it be an advantage or disadvantage, given reasoning for Option B, E above?
3) Three-tier (advantage): "Separating the tiers allows for more points to secure the system" <=== My understanding of this is, given that there are more points to secure it will be more secure (because you can contain the threat in that tier), but harder to secure (more work involved). Is this correct?
Any clarification would be greatly appreciated.
Thanks,
Marcelo
SCJP 1.4, SCWCD 1.4, SCBCD 1.3, SCJD, SCEA/OCMJEA
Live life to an interface, not an implementation!
Sharma Ashutosh
Bartender
Posts: 346
posted 6 years ago
"Maintainability" is the right answer for this question. As you have seperated business logic from presentation logic and now any changes in any one of them-you are required to make a change in only one layer/tier and not both of them as they are decoupled now.
Ashutosh Sharma
SCJP 1.2, SCEA 5, Brainbench certified J2EE Developer, Documentum Certified Professional
Blog : http://scea5-passingpart2and3.blogspot.com/
Claudiu Dumitrescu
Greenhorn
Posts: 29
posted 6 years ago
Maintainability is the correct answer in this case. And this is because they ask you what is the main advantage from separating the business from the presentation logic. They don't ask for the advantages of introducing a three-tier architecture into your system, case in which your observations would be valid.
posted 6 years ago
Sorry guys, I should of clarified. I'm not against the answer (maintainability would be the most correct answer - and I do understand why), but my concern is more with the explanations for the "incorrect" answers. They seem to contradict that of Cade's explanations.
SCJP 1.4, SCWCD 1.4, SCBCD 1.3, SCJD, SCEA/OCMJEA
Live life to an interface, not an implementation!
Claudiu Dumitrescu
Greenhorn
Posts: 29
Amandeep Singh
Ranch Hand
Posts: 850
posted 6 years ago
I totally agree with you. The reasoning given is so simple, not even talks up to technical depth.
You know what why Mark Cade's book is good because he is one of the co-creator of the exam. Other than this, I cannot appreciate much about the book.
You know what why Mark Cade's book is good because he is one of the co-creator of the exam. Other than this, I cannot appreciate much about the book.
SCJP 1.4, SCWCD 5, SCBCD 5, OCPJWSD 5,SCEA-1, Started Assignment Part 2
My blog- http://rkydesigns.blogspot.com
Rajan Choudhary
Ranch Hand
Posts: 196
Rajan Choudhary
Ranch Hand
Posts: 196
posted 6 years ago
Oops! I just realized that my post wasn't intended in this thread. Sorry about that. It happens when we open multiple windows and do a multitasking in the office.
Rajan Choudhary wrote:I just came out of the exam center & realized that proper understanding of JEE tutorial is must. All simulators, books are not going to help much. I will post my experience in another thread.
Oops! I just realized that my post wasn't intended in this thread. Sorry about that. It happens when we open multiple windows and do a multitasking in the office.
