Transaction Processing System (TPS)

ByAbdul-rehman Aslam

NATIONAL UNIVERSITY OF MODERN LANGUAGESISLAMABAD

13, December 2012

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Report

Table of Contents

1. Introduction:...................................................................................................................52. History:............................................................................................................................63. List of TPS Systems:......................................................................................................64. Transaction Processing Cycle:......................................................................................65. Processing types:............................................................................................................7

1. Batch processing:......................................................................................................72. Real-time processing:...............................................................................................73. Time-sharing:............................................................................................................74. Transaction processing:............................................................................................7

6. Transaction processing system features:.....................................................................87. Transaction Processing Modes:....................................................................................9

7.1. Characteristics of on-line transaction processing:....................................................97.2. Characteristics of batch transaction processing:.......................................................9

8. Transaction Processing Activities:................................................................................99. Transaction Processing Subsystems in a Firm:.........................................................1010. Outputs Provided by Transaction Processing Systems:.........................................1111. Types of Transactions:...............................................................................................11

11.1. Internal Transactions:...........................................................................................1111.2. External Transactions:..........................................................................................11

12. Characteristics of Transaction Processing Systems:...............................................1113. Processes of Transaction Processing System:.........................................................1114. References:..................................................................................................................12

1. Introduction:

Transaction processing (or OLTP for online transaction processing) is a class of information system in which the goal is to handle requests for updates to shared data from multiple clients. A crucial requirement is that the processing be completed while the client waits and an immediate response given. The automated teller machine (ATM) network is a typical example.

Transaction processing applications typically have some or all of these requirements:

data is shared among multiple clients requests are processed while a user is waiting multiple requests may be in progress at once

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scalability to large volumes of requests high reliability (few errors) high availability (minimal down-time)

So, what exactly is a transaction? A transaction is a series of operations on shared data taken together as a logical unit of work. It must succeed or fail as a unit and must proceed independently from other transactions that may be running at the same time. In other words, a transaction is a short program that accesses shared data and that must be executed in a way that obeys the ACID properties.

The standard example of a transaction is a transfer of funds from one account to another. The transaction has two parts. Crediting one account and debiting another. Clearly, it would be bad if one of these parts were to happen without the other.

Transaction processing is a key piece of computing infrastructure that enables applications in e-commerce, airline reservations, banking, and securities trading. When buzzwords like "enterprise" and "middleware" are thrown about, the meaning often boils down to transactional capabilities.

2. History:One of the first transaction processing systems was American Airline SABRE

system, which became operational in 1960. Designed to process up to 83,000 transactions a day, the system ran on two IBM 7090 computers. SABRE was migrated to IBM System/360 computers in 1972, and became an IBM product first as Airline control Program (ACP) and later as Transaction Processing Facility (TPF). In addition to airlines TPF is used by large banks, credit card companies, and hotel chains.

3. List of TPS Systems:Some of the common TPS systems are as follow:

IBM Transaction Processing Facility (TPF) - 1960. Unlike most other transaction processing systems TPF is a dedicated operating system for transaction processing running on IBM System z mainframes.

IBM Information Management System (IMS) - 1966. A joint hierarchical database and information management system with extensive transaction processing capabilities. Runs on OS/360 and successors.

IBM Customer Information Control System (CICS) - 1969. A transaction manager designed for rapid, high-volume online processing, CICS originally used standard system datasets, but now has a connection to IBM's DB/2 relational database system. Runs on OS/360 and successors and DOS/360 and successors, IBM AIX, VM, and OS/2. Non-mainframe versions are called TX Series.

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Tuxedo - 1980s. Transactions for UNIX, Extended for Distributed Operations developed by AT&T Corporation, now owned by Oracle Corporation. Tuxedo is a cross-platform TPS.

UNIVAC Transaction Interface Package (TIP) - 1970s. A transaction processing monitor for UNIVAC 1100/2200 series computers.

4. Transaction Processing Cycle:

Data Entry Activities Transaction Processing Activities File and Database Processing Document and Report Generation Inquiry Processing

5. Processing types:

1. Batch processing:

Batch processing is execution of a series of programs (jobs) on a computer without manual intervention. Several transactions, called a batch are collected and processed at the same time. The results of each transaction are not immediately available when the transaction is being entered there is a time delay.

2. Real-time processing:

"Real time systems attempt to guarantee an appropriate response to a stimulus or request quickly enough to affect the conditions that caused the stimulus. Each transaction in real-time processing is unique; it is not part of a group of transactions.

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3. Time-sharing:

Time sharing is the sharing of a computer system among multiple users, usually giving each user the illusion that they have exclusive control of the system. The users may be working on the same project or different projects, but there are usually few restrictions on the type of work each user is doing.

4. Transaction processing:

Transaction processing systems also attempt to provide predictable response times to requests, although this is not as critical as for real-time systems. Rather than allowing the user to run arbitrary programs as time-sharing, transaction processing allows only predefined, structured transactions. Each transaction is usually short duration and the processing activity for each transaction is programmed in advance.

6. Transaction processing system features:

The following features are considered important in evaluating transaction processing systems.

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.

Continuous availability:

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.

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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.

7. Transaction Processing Modes:

Transaction processing may be accomplished in one of two modes:

1. On-line mode2. Batch mode

7.1. Characteristics of on-line transaction processing:

1. Each transaction is completely processed immediately upon entry.

2. OLAP is the most common mode of used today.

3. More costly than batch processing.

4. Database is always up to date.

5. Require the use of fast secondary storage such as magnetic disks.

7.2. Characteristics of batch transaction processing:

1. Relies on accumulating transaction data over a period of time and then processing the entire batch at once.

2. Batch processing is usually cyclic: daily, weekly, or monthly run cycle is established depending on the nature of the transactions

3. Cheaper than on-line processing

4. Easier to control than on-line processing

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5. Database is constantly out of date

6. Batch processing is now being captured using disk files

8. Transaction Processing Activities:

The processing of individual transactions, of course, depends to a degree on their nature. The general elements of transaction processing include:

1. Data capture and validation

2. Transaction - dependent processing steps

3. Database maintenance

9. Transaction Processing Subsystems in a Firm:

Overall transaction processing, also known as data processing, reflects the principal business activities of a firm. The principal transaction processing subsystems in a firm are those supporting:

1. Sales

2. Production

3. Inventory

4. Purchasing

5. Shipping

6. Receiving

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7. Accounts payable

8. Billing

9. Accounts receivable

10. Payroll

11. General ledger

10. Outputs Provided by Transaction Processing Systems:

The outputs provided by TPSs may be classified as:

1. Transaction documents

2. Query responses

3. Reports

11. Types of Transactions:Note that the transactions can be internal or external. When a department orders

office supplies from the purchasing department, an internal transaction occurs, when a customer places an order for a product, an external transaction occurs.

11.1. Internal Transactions:Those transactions, which are internal to the company and are related with the

internal working of any organization. For example Recruitment Policy, Promotion Policy, Production policy etc.

11.2. External Transactions:Those transactions, which are external to the organization and are related with the

external sources, are regarded as External Transaction. For example sales, purchase etc.

12. Characteristics of Transaction Processing Systems:1. A TPS records internal and external transactions for accompany. It is a repository

of data that is frequently accessed by other systems.

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2. A TPS performs routine, repetitive tasks. It is mostly used by lower-level managers to make operational decisions

3. Transactions can be recorded in batch mode or online. In batch mode, the files are updated periodically; in online mode, each transaction is recorded as it occurs.

4. There are six steps in processing a transaction. They are data entry, data validation, data processing and revalidation, storage, -output generation, and query support.

13. Processes of Transaction Processing System:The seven steps in processing a transaction are: Data entry Data Capture Data validation Processing and revalidation Storage Output generation Query

14. References:

1. http://www.cbare.org/writing/Transactions/transactions.html2. http://www.docstoc.com/docs/1024659/Transaction-Processing-System3. http://en.wikipedia.org/wiki/Transaction_processing_system

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