TRANSACTION PROCESSING SYSTEM Liew Woei Song Muhammad Hofiz Achoson

INTRODUCTION Transaction Processing System

WHAT IS A TPS? an information system designed to process routine business transactions an information system designed to process routine business transactions seeks time- and cost-efficiency by automating repetitive operations in large volumes seeks time- and cost-efficiency by automating repetitive operations in large volumes interfaces with an organization’s other information systems, such as IRS, DSS, EIS interfaces with an organization’s other information systems, such as IRS, DSS, EIS centers around accounting and finance transactions centers around accounting and finance transactions e.g,, airline reservation systems, order entry/processing systems, bank’s account processing systems e.g,, airline reservation systems, order entry/processing systems, bank’s account processing systems

examples of transaction processing systems The components of a transaction processing system, including: 1. users of the information system as belonging to the same organization that owns the transaction processing system 2. participants as the people who conduct the information processing 3. people from the environment becoming participants in real time systems as they directly enter transactions and perform validation Examples of real time transaction processing, including: 1. reservation systems; 2. point of sale terminal;3. library loans Examples of batch processing, including: 1. clearing of presented cheques; 2. generation of bills; 3. systems that appear real time, computerising transactions as they occur, but actual updating is processed in batch, such as credit card transactions.

CHARACTERISTIC Transaction Processing System

PERFORMANCE Fast performance with a rapid response time is critical. Transaction processing systems are usually measured by the number of transactions they can process in a given period of time.

RELIABILITY The system must be available during the time period when the users are entering transactions. Many organizations rely heavily on their TPS; a breakdown will disrupt operations or even stop the business.

DATA INTEGRITY The system must be able to handle hardware or software problems without corrupting data. Multiple users must be protected from attempting to change the same piece of data at the same time, for example two operators cannot sell the same seat on an airplane.

EASE OF USE Often users of transaction processing systems are casual users. The system should be simple for them to understand, protect them from data- entry errors as much as possible, and allow them to easily correct their errors.

MODULAR GROWTH The system should be capable of growth at incremental costs, rather than requiring a complete replacement. It should be possible to add, replace, or update hardware and software components without shutting down the system.

TYPE Transaction Processing System

REAL-TIME PROCESSING Transactions may be collected and processed as in batch processing. Transactions will be collected and later updated as a batch when it's convenient or economical to process them. Historically, this was the most common method as the information technology did not exist to allow real-time processing. This is the immediate processing of data. It provides instant confirmation of a transaction. It may involve a large number of users who are simultaneously performing transactions which change data. Because of advances in technology, real- time updating is possible. BATCHPROCESSING

For video

storing/retrieving in transaction processing systems Storage of data in relational and flat-file databases in digital form as it has the ability to manipulate, store and retrieve along with process and display with digital technology. Data, is for large companies collected in batched format Retrieval of stored data to conduct further transaction is usually warehoused. Sequential, indexed sequential and hashed files generally store the data in databases. Transaction Processing Systems

storing/retrieving in transaction processing systems Sequential data storage are data records one after the other in entry or key field order, header stores and field order of each record in a data dictionary with a search completed using either binary or linear. Indexed sequential data storage are records stored in any order and with a separate index file, keeping matching key field items with the records position. This is faster, but continual updates to index file requires two files which must be maintained. Hashed file storage will divide the disk space into numbered locations, with key field. At the time that they are divided by the total locations a remainder is provided as storage location. Transaction Processing Systems

storing/retrieving in transaction processing systems data warehousing is the collection of data from a range of data sources. Transaction Processing Systems

Data Input Data Processing Output Generation Data Storage A Transaction Processing Model

Barcode Scanner POS TPS UPC Product DB Inventory DB Information Reporting System Customer Receipt Exception Reports UPC Price UPC & Quantity Product, Quantity, Date, Time, Price POS(Point Of Sale) TPS Purchasing DB Quantity, Date, Time

Transaction Data Processing Trans. File New Master File Old Master File Documents/ Reports Batch Processing

On-line Processing On-line Data Processing Documents/ Reports Transaction Data Inquiries/ Reponses Transaction Data Transaction Data

TPS APPLICATIONS Order Processing Order Processing Purchasing Purchasing Accounts Receivables & Accounts Payables Accounts Receivables & Accounts Payables Receiving & Shipping Receiving & Shipping Inventory on Hand Inventory on Hand Payroll Payroll General Ledgers General Ledgers

IS Transactions22 TRANSACTION STATES AND ADDITIONAL OPERATIONS (CONTINUED) ACTIVE PARTIALLY COMMITTED FAILD TERMINATED COMMITTED BEGIN TRANSACTION END TRANSACTION COMMIT ABORT Figure 19.4 State transition diagram illustrating the states for transaction execution READ / WRITE

RECOVERY PROCEDURE Transaction Processing System

WHY RECOVERY NEED? There is various reason leak fail transaction : There is various reason leak fail transaction : Computer failure Transaction error Concurrent control enforcement Physical problem A hardware, software, or network error occurs in the computer system during transaction execution. Some operations in the transaction may cause it to fail The concurrency control method may decide to abort the transaction. Natural disaster,theft, fire,etc

HOW SYSTEM RECOVERY THE TRANSACTION? TPS will go through recovery of database which involve backup, journal, checkpoint, and recovery manager TPS will go through recovery of database which involve backup, journal, checkpoint, and recovery manager Journal: contain transaction logs and database change logs Journal: contain transaction logs and database change logs Checkpoint: consists of the transaction start, terminate, commit or abort Checkpoint: consists of the transaction start, terminate, commit or abort