TRANSACTION PROCESSING SYSTEMS Option 1 Transaction Processing Systems

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TRANSACTION PROCESSING SYSTEMS Option 1: Transaction Processing Systems

TRANSACTION PROCESSING SYSTEMS Option 1: Transaction Processing Systems

Transaction Processing Systems Transaction Processing Systems are systems that collect, store, modify & retrieve

Transaction Processing Systems Transaction Processing Systems are systems that collect, store, modify & retrieve the transactions of an organisation. They are crucial to the operation of most finance, banking and electronic commerce operations. Transaction Processing is primarily concerned with data integrity. So – what is a transaction?

What is a transaction? TRANSACTIONS A transaction is a series of events that when

What is a transaction? TRANSACTIONS A transaction is a series of events that when performed together complete a unit of work. Each transaction is a complete success or a complete failure. If a transaction is successful, then all actions were completed. However, if one action fails then the transaction cannot be successful. A transaction can include events that perform actions on a single database, many databases or on a variety of info systems. Definition: A unit of work composed of multiple events that must all succeed or must all fail. Events perform actions that create/or modify data.

Characteristics of Transaction Processing Systems Transaction processing is one of the earliest commercial use

Characteristics of Transaction Processing Systems Transaction processing is one of the earliest commercial use of computer systems. We are going to examine… � Early examples of transaction processing systems � Manual transaction processing systems and features that make them suited to automation � Modern transaction systems – components and how they maintain accuracy of data

Early examples of transaction processing systems Come to page 366 of your text and

Early examples of transaction processing systems Come to page 366 of your text and read the section titled Historical Significance of Transaction Processing on pages 366 and 367.

Automation of Manual Transaction Processing of manual transactions must follow a strict sequence of

Automation of Manual Transaction Processing of manual transactions must follow a strict sequence of events. Each event must be completed AND acknowledged as completed before the next event commences. If any event fails then the entire transaction is aborted. EG. If a person withdraws $2000 from an account with only $1000 then an event must fail somewhere during the process and consequently the transaction must fail.

Automation of Manual Transaction Processing In a manual system events are completed by clerks

Automation of Manual Transaction Processing In a manual system events are completed by clerks or other personnel according to strict pre -defined rules. In large organisations there may be multiple clerks each with an individual role. In this scenario a single transaction is passed along the clerks until the events are complete and as such the transaction. Open your text to page 368 and read from “As a simple example let us consider…” through to the bottom of 370.

Components of Transaction Processing Systems Open your text to page 371 and read through

Components of Transaction Processing Systems Open your text to page 371 and read through the explanation of the components of a Transaction Processing System in relation to the ‘Information Systems’ diagram. Create a copy of the diagram in Word with brief explanations of the components in relation to TPS in general. Use the information from pages 371 – 375 of your text to summarise each section.

Data Integrity In any transaction processing system Data Integrity is critical. In previous topics

Data Integrity In any transaction processing system Data Integrity is critical. In previous topics we said that data integrity is “a measure of how correct and accurately data reflects its source. The quality of data” We also spoke about techniques for improving Data Integrity – Data Validation, Data Verification and Referential Integrity.

Data Integrity Data Validation is a check, at the time of collection, to ensure

Data Integrity Data Validation is a check, at the time of collection, to ensure data is reasonable and meets certain criteria. In relation to a TPS consider the example of an incorrect BPAY number being used to pay for a bill. Ultimately the transaction will fail but this may take time, resources and even cost to the parties involved.

Data Integrity Data Verification is a check to ensure the data collected and stored

Data Integrity Data Verification is a check to ensure the data collected and stored matches and continues to match the source of the data. In relation to a TPS consider the example of someone cancelling their credit card and not updating all of the relevant organisations who bill to that particular card of the change. Eg. Mr Cummings e-tag… Mr Cummings sponsor child… Mr Cummings insurance etc.

Data Integrity Referential Integrity ensures that all foreign keys in linked primary tables match

Data Integrity Referential Integrity ensures that all foreign keys in linked primary tables match a primary key in the related table. In relation to a TPS consider the example of entering an incorrect BPAY reference meaning that the primary records held in various databases cannot be linked to the customers payment.

Data Integrity ACID Properties For Transaction Processing we should aim for all transactions to

Data Integrity ACID Properties For Transaction Processing we should aim for all transactions to have the ACID properties. This stand for atomicity, consistency, isolation and durability. Read pages 377 – 379 of the text and complete the following table…

Data Integrity ACID Properties Property Atomicity Consistency Isolation Durability Definition Example

Data Integrity ACID Properties Property Atomicity Consistency Isolation Durability Definition Example