Exercise 11

1. Give a description in your own words of the ACID properties of a transaction.
A transaction is a single logical operation for a data. The ACID (atomicity, consistency, isolation, durability) is the measurement to ensure the reliable database transactions.

References

Wiki. (2010). ACID. Retrieved on 13 May 2010 from http://en.wikipedia.org/wiki/ACID


2. Describe a TP monitor environment. How can a TP monitor stop an operating system being overwhelmed?
TP monitor environment (TeleProcessing monitor or Transaction Processing monitor) is a control program to monitor and manage the transfer of data between multiple local and remote terminals and the application programs that serve them. It may also include programs that format the terminal screens and validate the data entered.

In a distributed client/server environment, a TP monitor provides integrity by ensuring that transactions do not get lost or damaged. It may be placed in a separate machine and used to balance the load between clients and various application servers and database servers. It is also used to create a high availability system by switching a failed transaction to another machine. A TP monitor guarantees that all databases are updated from a single transaction.

References

The Free Online Dictionary. (2010). TP Monitor. Retrieved on 13 May 2010 from http://encyclopedia2.thefreedictionary.com/TP+monitor