Description

Question 1: For each of the schedules, answer the following questions:

i. What is the precedence graph for the schedule?
ii. Is the schedule serializable? If so, what are all the equivalent serial schedules?

A.
𝑇” 𝑇$
Read (A)
Write (A)

Read (C)
Write (C)

Read (B)
Write (B)

B.
𝑇” 𝑇$
Read(X)
X = X – N

Write(X)
Read(Y)

Y = Y + N
Write(Y)

Read(X)
X = X + M

Write(X)

𝑇” 𝑇$
Read(X)
X = X – N
Write(X)

Read(Y)
Y = Y + N
Write(Y)

Read(X)
X = X + M
Write(X)
C.

D.
𝑇” 𝑇$ 𝑇%
Read(X)

Read(Y)

Write(X)

Read(Y)

Write(Y)

Write(Z)
Read(Z)
Write(Z)

Write(X)

E.

𝑇” 𝑇$ 𝑇%
Read(A)

Write(A)

Write(C)
Read(B)

Read(C)
Read(B)
Write (B)

Read( B)

Question 2: (Optional) Match the following schedules with terms in box on the right (i – viii). Note that:

Your answer:
Your answer:
Your answer:

TERMS:

i. Serializable schedule

ii. Dirty Read conflict
iii.
Unrepeatable read

iv.
Phantom read
v. Serial schedule

vi.
Lost update conflict
vii. Non-serial schedule

viii.
Use of UNDO logs

Your answer: