CSC365 Assignment 4 - Part 1 Solved

CSC365 
Assignment 4​ - Part 1 

Q1[10 points]. Create the precedence graph for the schedule: w​1(​ X), r​1(​ X), w​2(​ Y), r​3(​ X), w​1(​ Y), w​1(​ X). Based on the graph, determine whether the schedule is conflict-serializable.  

Q2[10 points]. What is the difference between serializable and conflict-serializable schedule. What is the relation between the two (is one of them a subset of the other)?

Q3[10 points]. Consider the following schedule:

 r​1(​ A);r​2(​ B);???;w​1(​ C);w​2(​ A);

What value for ??? will make the schedule not conflict-serializable. Give one such possible value.

Q4[20 points]. Consider the transactions ​T​1 and ​ ​T​2.​

T​1 :​ ​r​1(​ ​A​); ​w​1(​ ​A​); ​r​1(​ ​B​); ​w​1(​ ​B​);

T​2 : ​ ​r​2(​ ​B​); ​w​2(​ ​B​); r​​2​( ​A​); ​w​2(​ ​A​);

Give an example of a conflict-serializable schedule and non conflict-serializable schedule for the eight actions.

Q5[20  points]. Are the following schedules conflict-serializable?

a)  ​r​1(​ ​A​); ​w​1(​ B); ​r​2(​ B); w​​2​( C);​ r​3(​ C); ​w​3(​ A);

b)  ​w​3(​ ​A​); ​r​1(​ A); ​w​1(​ B); r​​2​( B);​ w​2(​ C); ​r​3(​ C);

Submission 

Please submit your work as a PDF file to polylearn OR hand in your work to me in person (you can do so on the final exam’s day).