Serializabilty in Transactions.
The idea is to read a schedule from the user and to test it if it is conflict serializable or not and to draw its precedence graph
in a simple manner ( T1—->T3——>T2 or T1—->T3——>T1 etc…).
I need a simple program in Java without interfaces(GUI).
CSC383 Programming Project
C o n fl i c t S e r i a l i z a b i l i t y i n
T r a n s a c t i o n s .
College of Computer and Information Sciences
King Saud University
S p r i n g 2 0 1 8
1 Introduction
A transaction, in the context of a database, is a logical unit that is independently executed for data retrieval or updates. In
relational databases, database transactions must be atomic, consistent, isolated and durable–summarized as the ACID
acronym. Two schedules are conflict-equivalent if one can be reached from the other through a series of swaps of adjacent
operations, where no swap falls into one of the following patterns:
the operations are by the same transaction
the operations use the same database element, and at least one is a write
A schedule is conflict-serializable if it is conflict-equivalent to some serial schedule.
Your goal in this project is to implement a Conflict Serializable Checker with two basic operations: test for conflict
Serializability and draw a simple precedence graph. Your program should be linked with a main program in-order to test
its functionality. Note: you should choose the appropriate data structure for the program.
2 Requirements In this project you are required to implement a Conflict Serializable Checker to fulfill the
following requirements:
1. Read the size of the schedule from the user.
2. The program takes a schedule from the user in this form: : “r1x”, “r2z”, “r1z”, “r3y”,
“r3y”,…
The first instruction “r1x” means: r = read, 1 = the transaction, x is the element
Let x be an arbitrary instruction, then:
x[0]: can take the form of r (read) or w (write) to set the operation
x[1]: can take the form of 1,2,3,…,n to set the transaction
x[2]: can take the form of a,b,c,…,z to set the element
3. Test for conflict Serializability.
4. Draw a simple precedence graph
3 Deliverable and Rules
The submission deadline is 07/05/2018 at 12:00 PM before the final Exam, you
should deliver:
1. A report written.
2. T h e Source code on a CD.
You have to read and follow the following rules:
1. This assignment is to be conducted by groups of exactly three students.
2. The students can implement their own data structures; use Java collections, or
any other library to achieve assignment’s requirements.
3. Every group member should participate in all parts of the assignment: de-
signing, programming, and writing the program and report. Members of the same
group may receive different marks according to their participation in the work.
4. The submitted program will be evaluated in a demonstration which all the group
members should attend.
5. Any member of the group who fails to attend the demonstration without a
proper excuse shall receive 0 in the demo mark.
6. In accordance with the university regulation, cheating in the project will be
penalized by the mark 0 in the project.
4 Appendix 1. Create a schedule: String[] schedule = {“r1x”, “r2z”, “r1z”, “r3y”, “r3y”, “w1x”, “w3y”,
“r2y”, “w2z”, “w2y”};
2. Create an instance of Schedule: Schedule obj = new Schedule(schedule);
3. Can call one of three methods: o obj.getSchedule(): returns the schedule
o obj.precedenceGraph(): returns a graphical representation of the precedence graph
o obj.conflictSerializable(): returns information on the schedule
Input: String[] schedule = {“r1x”, “r2z”, “r1z”, “r3y”, “r3y”, “w1x”, “w3y”, “r2y”, “w2z”, “w2y”};
Schedule obj = new Schedule(schedule);
System.out.println(obj.getSchedule());
System.out.println(obj.precedenceGraph());
System.out.println(obj.conflictSerializable());
Output: //getSchedule()
r1x, r2z, r1z, r3y, r3y, w1x, w3y, r2y, w2z, w2y,
//precedenceGraph()
3 -> 2
1 -> 2
//conflictSerializable()
Is Schedule Conflict-Serializable: True, Schedule is acyclic, thus it’s conflict serializable.
