CS 542 Distributed Database Systems
Prof. Bharat Bhargava

Assignment 1
Due: January 26, 2016

Written homework assignments are due at the start of class on the due date.


Note: The points of every question are listed. Answer briefly.

Q1: Write one page summary of ideas for each of the three papers identifying the problem and the solution. (15 points)
You may select any papers in distributed database, cloud computing area that you want to read or choose from the reading list or outside the list.
Three papers that can give you a quick background can be "The Raid Distributed Database System", "Concurrency Control in Database Systems" and "Building Distributed Database Systems".

Q2: Try to read the paper: The serializability of concurrent database updates, C. Papadimitriou, Journal of the ACM (JACM), 26(4), 1979
What are the different performance criteria for evaluating concurrency control algorithms? (10 points)
What is the difference between class DSR and 2PL? (10 points)
When DSR is equivalent to SR class of concurrency control? (10 points)

Q3: Give examples of transaction executions that lead to (10 points)
            a) lost update
            b) dirty read

Q4: What makes the problems in a distributed database system different (or complex) as compared to the problems in a single site system? List at least four differences. (10 points)

Q5: Is there any sense in running a (10 points)
            a) 'read only' transaction?
            b) 'write only' transaction?

Q6: Discuss the role of the following issues in distributed database system architecture: (10 points)
           (a) autonomy
           (b) heterogeneity
           (c) scalability.

Q7: Read the paper "Granularity of Locks and Degrees of Consistency in a Shared Data Base" by J. Gray, R. Lorie, G. Putzolu, I. Traiger.
What are advantages and disadvantages of multiple-granularity locks? (10 points)

Q8: What are advantages and disadvantages of a replicated database compared with a non-replicated database? (10 points)