Information Management

Information Management

Lecture 4Technology for Information Management

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Bibliography [1] Dave Chaffey, Steve Wood - Business Information

Management : Improving Performance Using Infomation Systems, 2005, Prentice Hall/Financial Times, (734 pages)

[2] Benson V., Tribe K. – Business Information Management, 2008, Ventus Publishing (83 pages)

[3] G. Somasundaram, Alok Shrivastava, Eds. - Information Storage and Management: Storing, Managing and Protecting Digital Information, 2009, Wiley Publishing, Inc (478 pages)

[4] Wikipedia

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Overview Technology infrastructure components Selecting computer components Selecting processors Selecting memory devices Selecting permanent storage Selecting output devices Selecting input devices Introduction to network technology Internet technology

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Technology infrastructure (TI) TI is the architecture of hardware,

software, content and data used to deliver information services to employees, customers and partners.

The domain of TI can be splited in: Organizational TI Computer system components Networking and telecommunications links Inter-organizational TI – the use of Internet

for information transfer

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A five layered model of TI [1, pg. 118]

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The TI is often implemented using a client-server model. The client–server model of computing is a distributed application that

partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients.

The word client can name a physical person or a software to access the server in the service of the physical person or of another software

The server can name a hardware used as storage or can provide applications for the clients. Also it can name a software used in a client-server manner for providing services and storage to clients.

So client-server refers to either the software model also to hardware or/and persons from the real world.

TI addresses both.

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Different types of servers [1,118] Web server. Manages http requests from client and acts

as a passive broker to other servers. Returns or serves web pages.

Merchant server. This is the main location of the application logic and integrates the entire application by making requests to the other server components.

Personalization server. Provides tailored content – may be part of commerce server functionality.

Payment commerce server. Manages payment systems and secure transactions.

Catalogue server. A document management server used to display detailed product information and technical specifications.

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CRM server. Stores information on all customer contacts.

ERP server. Required for information on stock availability and pricing from the customer. Will also need to be accessed for sales order processing and histories.

Logistics for distribution will also be arranged through the ERP server.

Network server. Used to manage access of employees to the company network.

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To manage the load of each server one ore more physical machines will be used.

For very large loads we have server farms with hundreds of servers.

An important decision in designing an technology infrastructure (TI) is to decide what is to be handled by the servers and what by the clients.

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What would the server and the client handle Data storage should be

predominantly on the server Query processing - on the server Display of graphics and text – on the

client Application logic – on the client or on

the server

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Three-tier client-server architecture [1, 120]

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Types of client computers Terminals PC:

Desktop Laptop Handheld – PDA (personal digital

assistant) Windows terminal or network computer

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Types of server computers Mainframes, mini-computers, microcomputers – for small

companies For large companies:

Blade servers - Compact ‘high-density’ servers comprising microprocessors and memory on a single circuit board to optimize the use of physical space.

Clusters of servers for increased stability and performance

Storage area network (SAN) – clusters + networked storage devices

Grid computing - the combination of computer resources from multiple administrative domains to reach a common goal [4]

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Types of server computers (2) Cloud computing - the delivery of computing as a

service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a utility (like the electricity grid) over a network (typically the Internet). [4]

Mainframes – large computers capable of hosting multiple OS which provide virtualization and hot swap capabilities. Better cost performance than PCs in large organizations.

Mini-computers. For example for web hosting.

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Computing architectures Centralized computing - a single mainframe or mini-

computer performs processing and provides storage for many users. Clients are text terminals or more sophisticated.

Personal computing – individual PCs are user for storage and performing user tasks

Distributed computing – clients are connected with multiple servers

Network computing – similar to centralized computing but with more performant client

Peer-to-peer (P2P) computing – each computer can be used as a server or a client at the same time

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Main components of a PC [1, 127]

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Selecting a processor (CPU) The factors for selecting a CPU are:

Manufacturer. Most known Intel and AMD. Processor architecture. RISC, multicore

processors, multiprocessor computers Clock speed. As the clock speed increases so

does the MIPS (millions of instructions per second).

System bus, chipset and motherboard. On the motherboard the system bus frequency (in MHz) and the chipset can affect the performance of the PC.

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Other processors There are other important

microprocessor that can affect the PC’s performances.

Graphics and audio processors are a good example. They are located on the motherboard or on separate graphic card respectively audio card.

NIC (network cards) are also equipped with microprocessors

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Memory devices Types of storage:

Volatile storage -RAM Permanent storage – ROM, HDD

ROM stores the BIOS (binary input and output system) which controls the hardware. It doesn’t affect the performance of the system, being standard PC component.

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RAM (random access memory) holds the OS, the running programs and their data. It is volatile. It is supplemented with virtual memory (swap file or page file) located on the HDD.

Few RAM determines high use of the virtual memory which is slower and thus decreases performances.

If RAM and virtual memory are full, the PC stops working or is very slow.

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Permanent storage Magnetic storage: HDD, floppy disks Optical storage: CD, DVD – Read Only

or Rewritable Tape storage: magnetic tape – high

capacity, used for backup, slow speed Solid state memory devices – flash

RAM

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Factors for selecting storage devices and media Capacity of the device or medium Speed of reading and writing:

magnetic media are the fastest, then optical media, then tape media

Cost of device Cost of removable media Need for permanent or removable

media

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Factors for selecting output devices: monitors Type of the monitor: CRT, LCD Size Resolution Number of colors supported Dot pitch (size of one pixel on the

screen)

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Factors in selecting printers Type of printer: dot matrix printer, plotter (used

for CAD), inkjet printer, laser printer Paper sizes supported, orientation Postscript or not Number of pages printed per minute (ppm) Capacity of the tonner Resolution – in dpi (dots per inch) at least 600

dpi, and 1200 for high resolution Number of colors supported Price

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Selecting input devices For selecting the mouse and keyboard

– select ergonomic models For selecting scanners – the ones that

protect the eyes

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Network technology Computer network - A communication system that

links two or more computers and peripheral devices to enable transfer of data between these computers [1, pg 142].

LAN (local area network) – a computer network spread on a small area, generally a building or an office.

WAN (wide area network) – a computer network covering a large area, eventually the whole Internet.

Wireless networking – LAN using wireless media Bluetooth – wireless technology for short range data

transmission

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ISDN connection (integrated services digital network) – communication through a phone line using two separate channels: one for data, the other for voice)

ADSL (asymmetric digital subscriber line) - communication through a phone line where the download data transfer rate is higher to the upload one. Also known as broadband services

Leased line – a line of communications that’s used exclusively by the company that has leased it

Secure virtual private network (VPN) – encrypt the data transmitted through the regular communications chanels

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WI-FI – high-speed wireless LAN. Wi-FI hotspot – location where

someone can connect freely to the Internet using a laptop equiped with wireless technology

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Telecommunications components Modem (modulator-demodulator) allows connection to

Internet through a phone line, eventually using a ISDN or ADSL line. Speed is measured in baud or bits per second (bps). Standard modem has 56.6 kbps

Hub or switch – equipment that is used to connect more computers using Ethernet cables

Bridge and router – connect different LANs or PCs. They offer a WAN line through which the LAN can connect to the Internet. Eventually are equipped with a firewall for data protection.

Repeater – amplifies the signal to increase the distance of transmission. Can be used for LANs with high dispersion in space to connect distant points.

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Internet technology TCP/IP (Transmission Control Protocol) is a transport-layer

protocol that moves data between applications. The Internet protocol is a network-layer protocol that moves data between host computers [1, pg. 150]

The data that is transmitted through the TCP/IP protocol is broken into packages.

IP address – a unique numerical address of a computer HTTP protocol – protocol of communication between web

browsers and web servers. URL (uniform resource locator) – web address of pages. It

contains also the protocol used to access that page. Ex. http, ftp

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HTML (hypertext markup language) – language that describes the web pages. It ensures that all pages are rendered the same not depending on the web browser used.

XML (eXtensible Markup Language) – language used to include data (e.g. databases) on the Internet. Since it has a lot of tags, it is better intended for machine reading than human reading. The DTD (document type definition) defines the structure of a certain XML file.

RDF (resource definition framework) – an element of HTML intended to facilitate standardized metadata.

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EDI (Electronic data interchange) – The exchange, using digital media, of structured business information, particularly for sales transactions such as purchase orders and invoices between buyers and sellers [1, pg. 144]

RossetaNet is a consortium of many of the world’s leading information technology, electronic components and semiconductor manufacturing companies working to create, implement and promote open e-business process standards [1, pg. 162].