Types of Processing of Data www ICTTeacher com

Types of Processing of Data www. ICT-Teacher. com

• There are different types of processing: • batch • interactive • transaction. • Characteristics of each type. • Appropriate contexts for their use.

Processing • Data may be processed in different ways according to what is most suitable. • Types: – Batch, – Pseudo real time, – Real time, – Interactive, – Transaction, – On-Line.

Transactions • Transactions are recorded events that happen everyday in the process of selling and purchasing goods and services. • Transactions usually refer to money, cashing a cheque at a bank is a transaction. • Transactions can refer to other activities, such as: – Taking out a library book, – Applying for a driving licence, – Taking the school register.

Files • Master File: – A collection of records holding information on a group of people or objects. – Each record will hold multiple fields of data. – Some fields will change regularly, some often and some seldom. • Transaction File: – A file holding information on events or things that change, some will be regular events, and some will be additions, updates or deletions. • Changes are recorded on the Transaction files, and when finished are transferred to the Master file in a single process.

Files • An employee holds a master file and transaction files for his employees. • What would some records be in the master file? • What files may be held as transactions? • What would be regular transactions? • What would be add, update and delete transactions?

Batch Processing • A large collection of similar transactions are put together over a period of time and then processed in one go. • This means that the processing is done at a convenient time for the operators or when the computers are less busy. • What could be an example of batch processing? • Some systems are not suitable for batch processing, – i. e. a flight control system…why?

How does Batch Processing Work? • Take for example a home order sales business. • Order applications are received by telephone, or by the Internet, or through the post, and transferred to data capture forms ready for processing. • The data capture forms will be collected until there are enough to do a batch process. These documents will be checked, control totals and batch headers will be added. • Data from the data capture forms will be entered into a database known as the transaction file.

• The data will be validated by the computer software to check that the data is reasonable. • What does reasonable mean? • The data will also be verified, this is done by using another operator to key in the same data. • How does the computer verify data? • Any errors found can be corrected, and re-input. • The process of transfer from transaction file to master file is normally done at a time when the computers are at their least busiest, e. g. overnight. • This process usually does not need an operator after first being set up. • After the master file has been updated, reports are printed off for management.

Real Time Processing • This is an instantaneous recording on the file or database of an event. • Computers need to respond instantly to data that is received. • A nuclear reactor will have many sensors feeding back information constantly to a computer, all of these readings are checked against safety limits. • Any data received outside will set off another set of instructions to control any safety devices. • A delay of even a few seconds may result in injury or death to the operators.

Pseudo Real Time Processing • This is a near instantaneous recording on a file or database. • The computers need to respond to an event but it need not be instantaneously. • An airline booking system needs to be updated every time a flight is booked, to avoid two people being booked onto one seat, but a delay of a few seconds to a minute will not affect this as the transaction will always take place (system programmed) before the next booking. • Customers can enquire whether seats are available and the operator can look up the database to see what seats are still available.

Interactive Processing • Known as On-Line processing as any file may need to be accessed immediately, - files are on disk not stored somewhere else. • Data is entered and processed into the system in one stage. • Queries and orders may be made over the telephone and Internet, confirmation is given and the stock database is amended in one step. • A customer invoice is produced, a copy goes to the warehouse for despatch.

What Mode of Processing? • Does the information output need to be completely up to date at all times? • Is there very high volumes of data that would use up computer time? • Can spare computer capacity be used overnight? • Expensive backup and recovery procedures for a real time procedure. • Can a combination of both be used?