CS54200: Distributed Database Systems
Prof. Bharat Bhargava

Homework 4 PDF
Due date: April 25, 2017


Note: Written homework assignments are due at the start of class on the due date. Answer each question briefly.


Q1: a) How can the ideas of "degrees of commitment" be used in increasing the performance of
       transaction processing during network partitioning?
       b) What is view-serializability and how it can be used in network partitioning?
       c) How can checkpoints be used to maintain consistency and help in recovery after a failure?

Q2: How would you change the design and algorithms for distributed database processing if there were
       multiple and frequent failures (like sites failing and recovering, network partitions, variable
       communication delays, large number of lost messages)?

Q3: What are the types of attacks in internet and mobile communications? How transaction-processing
       algorithms can be designed to deal with some of them?

Q4: What is the latency in LAN, WAN and in communicating with Cloud Services? Try to measure it
       using echo service or find it from papers under communication networks in CS542 course page.

Q5: How can you find at the time of merge if inconsistent updates have taken place while network
       was partitioned?