distributed data base


Unformatted Attachment Preview

Don't use plagiarized sources. Get Your Custom Essay on
distributed data base
Just from $13/Page
Order Essay

CMP626 Assign 3:
Questions 5.1, 5.2 and 5.3 from text book
5.1 Check the serializability of each one of the following schedules:
S1 = R1(X), R2(X), R3(X), W1(X), W3(X)
S2 = R2(X), R1(Y), W3(X), W2(X)
S3 = W1(X), R2(X), W3(X), W2(X)
S4 = R1(X), R3(X), R2(X), W2(Y), W3(X)
S5 = R3(X), W1(X), R1(X), W2(X)
Indicate all RW, WR, and WW conflicts and show all partial commitment orders forced by
these conflicts. Indicate if the schedule is serializable. If it is, what is the total commitment
order? If it is not, indicate the first operation that causes the problem.
5.2 Assume the following three transactions in Figure 5.31 and the order in which they work
with data items X and Y. Show three schedules that are created by applying (A) no-locking, (B)
1PL, and (C) 2PL to these transactions. For each schedule in (A), (B), and (C), you should show
all partial commitment orders (PCOs) caused by all RW, WR, and WW conflicts. Are these
schedules serializable? If yes, what is the serialization order? If not, why?
Figure 5.31 Concurrent transactions for Exercise 5.2.
5.3 Assume the three transactions in Figure 5.32 and the order in which they work with items X
and Y. Answer the following for these three transactions, if we use (A) no-locking, (B) 1PL, and
(C) 2PL for concurrency control. Show the schedules for (A), (B), and (C). Find out all partial
commitment orders for RW, WR, and WW conflicts. If the schedule is serializable, what is the
serialization order? If not, why? Are there any deadlocks?
Figure 5.32 Concurrent transactions for Exercise 5.3.
Questioon 4:
Consider the join graph and the following information:
size(EMP) = 100, size(ASG) = 200, size(PROJ) = 300, size(EMP 1 ASG) = 300,
and size(ASG 1 PROJ) = 200. Describe an optimal join program based on the
objective function of total transmission time.
Question 5: Apply the dynamic query optimization algorithm to the following query and illustrate the successive
detachments and substitutions by giving the monorelation subqueries generated.
HINT: Use detachment example from class slides
WHERE (DUR > 12 OR RESP = “Analyst”)
AND (TITLE = “Elect. Eng.”
OR ASG.PNO < "P3") AND (DUR > 12 OR RESP NOT= “Analyst”)

Purchase answer to see full

Order a unique copy of this paper
(550 words)

Approximate price: $22

Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages

Order your essay today and save 15% with the discount code ESSAYHELP