9.4.1 Transaction Processing Systems
Glossary
Term Definition
Transaction A unit of work composed of multiple events that must all succeed or
must all fail. Events perform actions that create and/or modify data
that is eventually stored in an information system.
Transaction TPS are information systems that process the transactions which
Processing System occur within an organisation, and collect, store, modify and retrieve
records of transactions
Batch Batch processing is delayed transaction which collects the
transaction data as a group and processes it at a later time e.g.
paying electricity bills, receiving your salary, paying phone bills,
cheque clearance
Real-Time Real-time transaction processing, also known as online transaction
processing (or OLTP) is when transactions are completed
immediately after being initiated a e.g. airline reservation systems,
banking transaction systems
Transaction Transaction processing monitors are software applications that
processing monitor coordinate the transaction processing of large TPSs. The software
provides a standard interface between the input devices, the
transaction processing application programs and the DBMS. It also
provides data security and is an important part of real-time
transaction.
Data Integrity A measure of how correct and accurately data reflects its source.
The quality of the data. Harder to check data integrity than data
validation.
Data Validation A check, at the time of data collection, to ensure the data is
reasonable and meets certain criteria.
Data Verification A check to ensure the data collected and stored matches and
continues to match the source of the data. Maintaining data
integrity over time.
POS Point of Sale. Refers to the location where transactions occur, such
as the checkout/cashier counter in a store, or it can apply to the
hardware & software: electronic cash register systems, touch-
screen display, barcode scanners, receipt printers
POST (Point-of-Sale Terminals) is an electronic device used to process
card payments at retail locations. It allows the store management
to easily monitor sales and stock levels to ensure that store has
sufficient stock, and also allows to view the spending patterns of
customers.
Transaction log A record of the original data and changes made as part of a
transaction.
,Resource manager A software product that provides an interface between the
resource and the transaction processing monitor.
Referential Ensuring all foreign keys in linked tables match a primary key in the
integrity related table.
Record locking Locking data involved in a transaction to prevent other transaction
processes from changing the data. Other transactions must wait for the
lock to be released before they proceed.
Two-phase commit Refers to events being performed temporarily (phase one) during a
transaction and then being committed (phase two) if the
transaction completes successfully. The first phase is recorded in
the transaction log and also involves the record being locked. The
second phase alters the actual data permanently and releases the
record lock.
Commit Permanently write the transaction into the database, occurs when
transaction has been fully successful.
Rollback Transaction is not written and instead details are stored in an error file or
log describing the problems that caused the error. It occurs when the
transaction has been unsuccessful
UPC Universal Product Code - 12 digit number for products that is usually
printed with an equivalent barcode on the product’s packaging
Rapid Response Fast performance where the time from input of transaction to output
must be a few seconds or less
Reliability Well-designed backup and recovery with a low failure rate
Inflexibility Treat every transaction equally and processed in the same way regardless
of the user, customer or time of day.
Controlled Maintain specific requirements for the roles and responsibilities of
processing different employees.
Atomicity When all steps involved in transaction are completed successfully. If any
step fails, entire transaction is abandoned.
Consistency Ensures transactions take data from one consistent state and then when
the transaction completes the data is left in a consistent state. E.g.
ensuring when a product is bought that a sale has gone up and stock has
also gone down.
Isolation Ensures transactions independently process data without interfering or
being influenced by other transactions that are currently executing.
Record locking, transaction logs and the “two-phase commit” nature of
transactions all influence each other and combine to implement isolation
property.
Durability Ensures that the transaction is absolutely permanent and that it is written
in secondary storage so that all changes are saved and recorded.
,Barcode A machine-readable code in the form of numbers and a pattern of
parallel lines of varying widths, printed on an item and used
especially for stock control.
Backup To copy files to a separate secondary storage device as a precaution
in case the first device fails or data is lost. It is the process of making
a copy of data in case the original is lost or damaged.
Recovery The opposite of the backup process where the backup copy of the
data is restored and placed back into the system.
Unique Identifiers A random/ serial number used to identify an individual entity
(including product, employee, customer etc.). This includes
barcodes, employee numbers, SKU numbers, UPC code etc.
Data Mining Data mining is a decision support technique that examines raw data
to try discover hidden patterns and relationships and presents new
information that was not originally intended to be present within
the data.
Data Marts A reorganised summary of specific data from the data warehouse
and/or transaction database. Each data mart aims to meet specific
decision support needs of a particular department and they
improve the efficiency of information transaction from data
warehouses. They are created by running select queries that
summarise the data in the transaction database/ data warehouse
and the results are used to create a new table within the data mart.
Summaries must be chosen carefully so that required detail is
retained and not lost.
Data Warehouse A large database that includes historical copies of data from each of
an organisation’s operational databases.
Management A computer-based system that transforms data within transaction
Information processing systems into information to assist in the management of
Systems (MIS) business operations.
Decision Support A computer-based information system that provides information to
Systems (DSS) managers to assist the decision making process, which presents
possible solutions and is able to assess the likely consequences of
decisions.
Enterprise Systems A large organisation, for example government departments, large
corporations and universities. It is any system that performs
processes central to the overall operation of an enterprise.
Bias An inclination or preference towards an outcome. Bias unfairly
influences the outcome.
Characteristics of Transaction Processing Systems
Transaction
- Transaction processing systems are crucial to the operation of most finance, banking and
electronic commerce organisations. Transaction processing is primarily concerned with
maintaining data integrity.
, - Essentially a single event that changes something, many different types e.g. customer
orders, receipts, invoices, payments
- Examples of TPS: selling goods using POS, processing credit card payments, motel
reservation, theatre/concert tickets, airline system (reservations, seating, meal types)
- Example of transaction at video game store: customer buying video game and pays with
cash is sale transaction. Other transactions occur: amount of cash at register has gone up,
inventory of video game has gone down
- 4 main characteristics of TPS: rapid response, reliability, inflexibility, controlled processing
Components
Purpose
- All the components work together to meet the purpose
- Information system that collects, stores, modifies and retrieves transactions of organisations
- Must have rapid response, reliability, inflexibility, controlled processing
Data
- Stored in databases, usually relational
- Data transformed into information by system’s information processes
- TPS issue is ensuring data integrity: if another user or process views/alters data during
transaction; if data received from another system has problems; if system fails during
transaction
- Issues resolved by recording detail of all transactions in transaction file or log
- Transaction log used to enable committing or rolling back of events within transactions
- When an event occurs as part of a transaction, two possibilities arise:
o Changed/added records are recorded in transaction log, no change made to actual
data in master file. If transaction committed, records in transaction log
replace/added to master file. If rolled back, records are not written to master file.
o Changed/added records made immediately to actual data within master file, copies
of original unchanged data are recorded in transaction log. If transaction committed,
nothing needs to occur. If transaction rolled back, record in transaction file is copied
back over actual data in master file.
- Most current DBMSs record both before & after versions of data within logs, allowing
implementation of both possibilities, meaning the log is of all activities performed on data
, Information Technology
- Hardware and software requirements vary enormously as TPS vary enormously in both size
and scope
- Possible hardware for TPS includes:
o Server machines providing access to database
o Storage devices with sufficient capacity and data access speeds to support size of
database and number of users. Commonly RAID storage used.
o Communication devices and transmission media to support number of required
users and data access speeds
o Backup devices such as tape drives, tape libraries, CD burners and DVD burners
o Client workstations for running client applications
- Possible software for TPS includes:
o DBMS software to manage and control transactions performed on linked databases
o Client applications installed on client workstations
o Proprietary software applications designed and developed to meet needs of specific
organisation. Proprietary: software produced for specific system or organisation and
generally owned by that organisation
o Transaction processing monitors (TPMs). Main task is to ensure the integrity of
transactions that include events which execute on different servers and/or systems.
Each server/system performs own transaction, reports outcome (success/failure) to
resource manager, communicates with TPM who controls commit or rollback of total
transaction in response.
Processes
- Data capture and updates of transactional data
- Mainly storage & retrieval, but also collecting, analysing, processing
- The actual processing of transactions includes the collection, editing, manipulation and
storage of data.
Participants
- Anybody who interacts directly with a TPS, including people who work for the organisation
that operates TPS, people (often customers) who enter data that initiates transactions
- Participants are the people who enter the data, including data entry operators, customer
service operators, people working at checkouts and anyone carrying out the tasks required
to process the data.
- People in the environment only become participants in online real time transactions, as they
are performed immediately in response to input. However in batch processes, no
transaction processing occurs or is initiated by that person therefore aren’t participants.
Users
- People who benefit from the TPS, but do not enter data themselves.
- Indirect users are not participants, they send and/or receive data from the system but do
not directly cause its entry or display, e.g. customer receiving a monthly bank statement in
the mail, they are indirect user because they did not initiate the generation of the statement
directly
Glossary
Term Definition
Transaction A unit of work composed of multiple events that must all succeed or
must all fail. Events perform actions that create and/or modify data
that is eventually stored in an information system.
Transaction TPS are information systems that process the transactions which
Processing System occur within an organisation, and collect, store, modify and retrieve
records of transactions
Batch Batch processing is delayed transaction which collects the
transaction data as a group and processes it at a later time e.g.
paying electricity bills, receiving your salary, paying phone bills,
cheque clearance
Real-Time Real-time transaction processing, also known as online transaction
processing (or OLTP) is when transactions are completed
immediately after being initiated a e.g. airline reservation systems,
banking transaction systems
Transaction Transaction processing monitors are software applications that
processing monitor coordinate the transaction processing of large TPSs. The software
provides a standard interface between the input devices, the
transaction processing application programs and the DBMS. It also
provides data security and is an important part of real-time
transaction.
Data Integrity A measure of how correct and accurately data reflects its source.
The quality of the data. Harder to check data integrity than data
validation.
Data Validation A check, at the time of data collection, to ensure the data is
reasonable and meets certain criteria.
Data Verification A check to ensure the data collected and stored matches and
continues to match the source of the data. Maintaining data
integrity over time.
POS Point of Sale. Refers to the location where transactions occur, such
as the checkout/cashier counter in a store, or it can apply to the
hardware & software: electronic cash register systems, touch-
screen display, barcode scanners, receipt printers
POST (Point-of-Sale Terminals) is an electronic device used to process
card payments at retail locations. It allows the store management
to easily monitor sales and stock levels to ensure that store has
sufficient stock, and also allows to view the spending patterns of
customers.
Transaction log A record of the original data and changes made as part of a
transaction.
,Resource manager A software product that provides an interface between the
resource and the transaction processing monitor.
Referential Ensuring all foreign keys in linked tables match a primary key in the
integrity related table.
Record locking Locking data involved in a transaction to prevent other transaction
processes from changing the data. Other transactions must wait for the
lock to be released before they proceed.
Two-phase commit Refers to events being performed temporarily (phase one) during a
transaction and then being committed (phase two) if the
transaction completes successfully. The first phase is recorded in
the transaction log and also involves the record being locked. The
second phase alters the actual data permanently and releases the
record lock.
Commit Permanently write the transaction into the database, occurs when
transaction has been fully successful.
Rollback Transaction is not written and instead details are stored in an error file or
log describing the problems that caused the error. It occurs when the
transaction has been unsuccessful
UPC Universal Product Code - 12 digit number for products that is usually
printed with an equivalent barcode on the product’s packaging
Rapid Response Fast performance where the time from input of transaction to output
must be a few seconds or less
Reliability Well-designed backup and recovery with a low failure rate
Inflexibility Treat every transaction equally and processed in the same way regardless
of the user, customer or time of day.
Controlled Maintain specific requirements for the roles and responsibilities of
processing different employees.
Atomicity When all steps involved in transaction are completed successfully. If any
step fails, entire transaction is abandoned.
Consistency Ensures transactions take data from one consistent state and then when
the transaction completes the data is left in a consistent state. E.g.
ensuring when a product is bought that a sale has gone up and stock has
also gone down.
Isolation Ensures transactions independently process data without interfering or
being influenced by other transactions that are currently executing.
Record locking, transaction logs and the “two-phase commit” nature of
transactions all influence each other and combine to implement isolation
property.
Durability Ensures that the transaction is absolutely permanent and that it is written
in secondary storage so that all changes are saved and recorded.
,Barcode A machine-readable code in the form of numbers and a pattern of
parallel lines of varying widths, printed on an item and used
especially for stock control.
Backup To copy files to a separate secondary storage device as a precaution
in case the first device fails or data is lost. It is the process of making
a copy of data in case the original is lost or damaged.
Recovery The opposite of the backup process where the backup copy of the
data is restored and placed back into the system.
Unique Identifiers A random/ serial number used to identify an individual entity
(including product, employee, customer etc.). This includes
barcodes, employee numbers, SKU numbers, UPC code etc.
Data Mining Data mining is a decision support technique that examines raw data
to try discover hidden patterns and relationships and presents new
information that was not originally intended to be present within
the data.
Data Marts A reorganised summary of specific data from the data warehouse
and/or transaction database. Each data mart aims to meet specific
decision support needs of a particular department and they
improve the efficiency of information transaction from data
warehouses. They are created by running select queries that
summarise the data in the transaction database/ data warehouse
and the results are used to create a new table within the data mart.
Summaries must be chosen carefully so that required detail is
retained and not lost.
Data Warehouse A large database that includes historical copies of data from each of
an organisation’s operational databases.
Management A computer-based system that transforms data within transaction
Information processing systems into information to assist in the management of
Systems (MIS) business operations.
Decision Support A computer-based information system that provides information to
Systems (DSS) managers to assist the decision making process, which presents
possible solutions and is able to assess the likely consequences of
decisions.
Enterprise Systems A large organisation, for example government departments, large
corporations and universities. It is any system that performs
processes central to the overall operation of an enterprise.
Bias An inclination or preference towards an outcome. Bias unfairly
influences the outcome.
Characteristics of Transaction Processing Systems
Transaction
- Transaction processing systems are crucial to the operation of most finance, banking and
electronic commerce organisations. Transaction processing is primarily concerned with
maintaining data integrity.
, - Essentially a single event that changes something, many different types e.g. customer
orders, receipts, invoices, payments
- Examples of TPS: selling goods using POS, processing credit card payments, motel
reservation, theatre/concert tickets, airline system (reservations, seating, meal types)
- Example of transaction at video game store: customer buying video game and pays with
cash is sale transaction. Other transactions occur: amount of cash at register has gone up,
inventory of video game has gone down
- 4 main characteristics of TPS: rapid response, reliability, inflexibility, controlled processing
Components
Purpose
- All the components work together to meet the purpose
- Information system that collects, stores, modifies and retrieves transactions of organisations
- Must have rapid response, reliability, inflexibility, controlled processing
Data
- Stored in databases, usually relational
- Data transformed into information by system’s information processes
- TPS issue is ensuring data integrity: if another user or process views/alters data during
transaction; if data received from another system has problems; if system fails during
transaction
- Issues resolved by recording detail of all transactions in transaction file or log
- Transaction log used to enable committing or rolling back of events within transactions
- When an event occurs as part of a transaction, two possibilities arise:
o Changed/added records are recorded in transaction log, no change made to actual
data in master file. If transaction committed, records in transaction log
replace/added to master file. If rolled back, records are not written to master file.
o Changed/added records made immediately to actual data within master file, copies
of original unchanged data are recorded in transaction log. If transaction committed,
nothing needs to occur. If transaction rolled back, record in transaction file is copied
back over actual data in master file.
- Most current DBMSs record both before & after versions of data within logs, allowing
implementation of both possibilities, meaning the log is of all activities performed on data
, Information Technology
- Hardware and software requirements vary enormously as TPS vary enormously in both size
and scope
- Possible hardware for TPS includes:
o Server machines providing access to database
o Storage devices with sufficient capacity and data access speeds to support size of
database and number of users. Commonly RAID storage used.
o Communication devices and transmission media to support number of required
users and data access speeds
o Backup devices such as tape drives, tape libraries, CD burners and DVD burners
o Client workstations for running client applications
- Possible software for TPS includes:
o DBMS software to manage and control transactions performed on linked databases
o Client applications installed on client workstations
o Proprietary software applications designed and developed to meet needs of specific
organisation. Proprietary: software produced for specific system or organisation and
generally owned by that organisation
o Transaction processing monitors (TPMs). Main task is to ensure the integrity of
transactions that include events which execute on different servers and/or systems.
Each server/system performs own transaction, reports outcome (success/failure) to
resource manager, communicates with TPM who controls commit or rollback of total
transaction in response.
Processes
- Data capture and updates of transactional data
- Mainly storage & retrieval, but also collecting, analysing, processing
- The actual processing of transactions includes the collection, editing, manipulation and
storage of data.
Participants
- Anybody who interacts directly with a TPS, including people who work for the organisation
that operates TPS, people (often customers) who enter data that initiates transactions
- Participants are the people who enter the data, including data entry operators, customer
service operators, people working at checkouts and anyone carrying out the tasks required
to process the data.
- People in the environment only become participants in online real time transactions, as they
are performed immediately in response to input. However in batch processes, no
transaction processing occurs or is initiated by that person therefore aren’t participants.
Users
- People who benefit from the TPS, but do not enter data themselves.
- Indirect users are not participants, they send and/or receive data from the system but do
not directly cause its entry or display, e.g. customer receiving a monthly bank statement in
the mail, they are indirect user because they did not initiate the generation of the statement
directly
