Client-Server Processing, Parallel Database Processing and Distributed Database Systems. KEVIN ROBERTS ANIKET MURLIDHARAN

Q1. Which of following is not a goal of Distributed Database Goals  B. Increased corporate control over data – This is not a goal because the data should be located so that 80 percent of the requests are local. Local employees and management understand issues related to data better than management at remote locations.

Q2. Which of the following is true?  A. There is only one coordinator for each transaction in the two- phase commit protocol – Only one node is designated the coordinator and the coordinator initiates all transactions.

Q3. An overriding design issue in client-server database architecture is? C. Division of processing - The allocation of tasks to clients and servers is an overriding design issue. Must be stable, secure and efficient.

Q4. In a distributed DBMS, the distributed data manager… D. All of the above – The above options are three of the primary duties of the distributed data manager.

Q5. Which of the following is not true? D. All of the above – All of the above are not true.

Why is Global query optimization important?  Queries performance is often critical for client applications  Resource usage will be reduced (input and output processing)  The network characteristics can greatly affect optimization and can be planned for to increase performance. Wide area networks have high communication costs while local networks have low communication costs.  Requires both local and global optimization  Variance in performance is often large in distributed systems.  Often involves dynamic optimization when a site is offline

What are some of the pitfalls of developing client–server systems.  It is often difficult to convert an existing system to the client-server model.  Division of processing can be difficult to manage. Tasks must be designated to either the client or server.  Process management for the client and server can be difficult to manage and often requires middleware to route the queries to the proper destination.  Middleware is also often needed to maintain efficient message processing even when a large number of clients are being handled.