Database Systems and Business Intelligence

MIS Chapter 7: Database SystemsFilmon Habtemichael

IntroductionWe are navigating across the technological dimension of MISPreviously we have seen Hardware and Software technologies in relation to MISSince you are studying Database courses in detail, this lecture will focus less in the technical details

IntroductionThe information systems we have been discussing in previous chapters are all databasesDSSMISESSA well-designed and well-managed database is an extremely valuable tool in supporting decision making.

Recap- Hierarchy of Data

The database ApproachTraditional approach to data managementAn approach whereby separate data files are created and stored for each application program.

Database approach to data managementAn approach whereby a pool of related data is shared by multiple application programs

Traditional Approach

Problems with Traditional approachThe resulting problems are Data redundancy and inconsistency, Program-data dependence, Inflexibility, Poor data security, and Inability to share data among applications.

Problems with Traditional approachData redundancy is the presence of duplicate data in multiple data files so that the same data are stored in more than one place or location.Occurs when different groups in an organization independently collect the same piece of data and store it independently of each otherwastes storage resources and also leads to data inconsistency

Problems with Traditional approachData Inconsistency: The same attribute may have different valuesE.g. Change in Student ID, Change in Date etcE.g 2 Different coding system (like cloth retailers and others

Problems with Traditional approachProgram-Data DependenceChanges in programs require changes to the data.One program might be modified from a five-digit to a nine-digit zip code. If the original data file were changed from five-digit to nine-digit zip codes, then other programs that required the five-digit zip code would no longer work properlyLack of Flexibilitycan deliver routine scheduled reports, but it cannot deliver ad hoc reports or respond to unanticipated information requirements in a timely fashionPoor SecurityManagement may have no way of knowing who is accessing or even making changes to the organizations data.Lack of Data Sharing and AvailabilityInformation cannot flow freely across different functional areas or different parts of the organization.

The Database Approach to Data Management

Database management systemA DBMS is software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs.End user doesnt need where and how the data are actually stored.This is done by separating the logical and physical views of the data. The logical view presents data as they would be perceived by end users or business specialists, whereas the physical view shows how data are actually organized and structured on physical storage media.

Advantages

Disadvantages

Data ModelingIs one of the tools database designers use to show the logical relationships among dataA data model is a diagram of entities and their relationships. Data modeling usually involves understanding a specific business problem and analyzing the data and information needed to deliver a solution.Enterprise data modeling is data modeling done at the level of the entire enterprise.E.g. Entity-relationship (ER) diagrams

The Relational Database ModelThe most popular type of DBMS todayThere are other models too (flat files, hierarchical, and network models)Data represented as two-dimensional tablesExamples of Relational models areOracle (current market leader)IBM DB2 (second market leader)Microsoft SQL Server (third market leader)Sybase, Microsoft Access, and MySQL.

Relational DB termsProjectingManipulating data to eliminate columns in a table.JoiningManipulating data to combine two or more tables.LinkingData manipulation that combines two or more tables using common data attributes to form a new table with only the unique data attributes.

Non relational databasesFor over 30 years, relational database technology has been the gold standardRelational DBMS and data warehouse products are not well-suited for organizing and analyzing big data or data that do not easily fit into columns and rows used in their data models.Non-relational database management systems use a more flexible data model and are designed for managing large data sets across many distributed machinesCompanies are turning to NoSQL non-relational database services forCloud computing, unprecedented data volumes, massive workloads for WebOracle NoSQL Database is an example

Data CleanupNamePhoneGenderDues paidDate paidRahel K07111213Female250 Nakfa15 OctoberNahom H/mariam07122332Male300 nalfa15 OctoberNahom H/mariam07603476Male300 nakfa25 october

The process of looking for and fixing inconsistencies to ensure that data is accurate and complete. Consider below the database of sports gym

Finding the AnomaliesNahom paid his dues twice in October, hence the data is redundantNotice that the data in the database is also inconsistent: Nahom has changed his phone number, but only one of the records reflects this changeReducing this databases reliability is the lack of a primary key to uniquely identify Nahom H/mariams record. The first Nahom could Nahom Hailemariam , but the second might be Nahom HabtemariamThese problems and irregularities in data are called anomalies.

Overview of database files- Flat FileSimple database program whose records have no relationship to one another.do not use any of the database modelsMany spreadsheet and word processing programs have flat file capabilities.Microsoft OneNote is designed to let people put ideas, thoughts, and notes into a computer file.

One note

Single UserA database installed on a personal computerE.g. Microsoft Office Access and FileMaker ProInfoPath has built-in forms that can be used to enter expense information, timesheet data, and a variety of other information.

Multiple UsersSmall, midsize, and large businesses need multiuser DBMSs to share information throughout the organization over a network.These more powerful, expensive systems allow dozens or hundreds of people to access the same database system at the same time

Providing a User ViewDBMS is responsible for access to a databaseOne of the first steps in installing and using a large database involves telling the DBMS the logical and physical structure of the data and relationships among the data in the database for each user. This description is called a schema (as in schematic diagram).

contA schema can be part of the database or a separate schema file.Schemas are entered into the DBMS via a data definition language (DDL) which is a collection of instructions and commands used to define and describe data and relationships in a specific database.

contAnother important step in creating a database is to establish a data dictionary, a detailed description of all data used in the database. The data dictionary contains the following dataName of the data item Aliases or other names that may be used to describe the item Range of values that can be used Type of data (such as alphanumeric or numeric)Amount of storage needed for the item Notation of the person responsible for updating it and the various users who can access it List of reports that use the data item

Storing and Retrieving DataOne function of a DBMS is to be an interface between an application program and the database. When an application program needs data, it requests the data through the DBMS.Two or more people or programs attempting to access the same record in the same database at the same time can cause a problemConcurrency control can be used to avoid this potential problem. One approach is to lock out all other application programs from access to a record if the record is being updated or used by another program.

Manipulating Data and Generating ReportsSome databases use Query-by-Example (QBE), which is a visual approach to developing database queries or requests.

contIn other cases, database commands can be used in a programming languageSELECT * FROM ICT_STUDENTSWHERE COURSE = MIS.In general, the commands that are used to manipulate the database are part of the data manipulation language (DML). which allows managers and other database users to access, modify, and make queries about data contained in the database to generate reports

Database AdministrationA DBA is expected to have a clear understanding of the fundamental business of the organization, Be proficient in the use of selected database management systems andStay abreast of emerging technologies and new design approaches.

contThe role of the DBA is to plan, design, create, operate, secure, monitor, and maintain databases. Typically, a DBA has a degree in computer science or management information systems and some on-the-job training with a particular database productThe DBA also works with programmers as they build applications

Popular Database Management SystemsThe popular DB2 relational database from IBM and The Sybase IQ database are available on the Linux operating system.A new form of database system is emerging that some refer to as Database as a Service (DaaS) and others as Database 2.0Popular companies like Google and Microsft are moving in the DaaS direction.

Special-Purpose Database SystemsIsraeli Holocaust Database (www.yadvashem.org)contains information on about three million people in 14 languagesiTunesstore music and video catalog is a special-purpose database system.Morphbank (www.morphbank.net)allows scientists from around the world to upload and share biological and microscopic photographs and descriptions that support research in many areas.

Selecting a Database Management SystemDatabase size: The number of records in the databaseDatabase cost: The purchase or lease costs of the databaseConcurrent users: The number of people who need to use the database at the same time (the number of concurrent users)Performance: How fast the database is able to update recordsIntegration: The ability to be integrated with other applications and databasesVendor: The reputation and financial stability of the database vendor

Using Databases with Other SoftwareFront-end application is one that directly interacts with people or users. Marketing researchers often use a database as a front end to a statistical analysis program.Back-end application interacts with other programs or applications; it only indirectly interacts with people or users.

Linking the Company Database to the InternetDeveloping a seamless integration of traditional databases with the Internet is often called a semantic Web.Good side: convenient for individual users, and increases effectiveness and efficiency for businesses and organizations. E,g eBay, amazon.com, Apples itunesBad side: half a million database servers were vulnerable to attack Google is rolling out a DBMS that will provide patients and physicians with one storage location for all medical records, accessed through a Web browser Google plans to encrypt the data and ask authenticationBut can reduce the number of paper forms and clerical errors

Linking the Company Database to the Internet

Users access an organizations internal database through the Web using their desktop PCs and Web browser software.

Data Warehouses, Data Marts, and Data MiningA data warehouse is a database that holds business information from many sources in the enterprise, covering all aspects of the companys processes, products, and customersA data warehouse stores historical data that has been extracted from operational systems and external data sourcesThis data is cleaned up to remove inconsistencies and integrated to create a new information database that is more suitable for business analysis.

Online Transaction Processing VS Data Warehousing

THE CHALLENGE OF BIG DATABig data doesnt refer to any specific quantity, but usually refers to data in the petabyte and exabyte rangeA single jet engine is capable of generating 10 terabytes of data in just 30 minutes there are more than 25,000 airline flights each day.Even though tweets are limited to 140 characters each, Twitter generates over 8 terabytes of data daily

Data MartsA subset of a data warehouse.Used to small and medium-sized businesses and to departments within larger companies.Instead of storing all enterprise data in one huge database, data marts contain a subset of the data for a single aspect of a companys business

Data MiningData mining is an information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse.The University of Maryland- forecast terrorist behavior based on past actionsExtensively in marketing to improve customer retention; Pricing analysis; and customer segmentation analysisE-commerce presents another major opportunity for effective use of data mining.

contPredictive analysis is a form of data mining that combines historical data with assumptions about future conditions to predict outcomes of eventsMy space, Facebook and others mines the data of all of its members to determine which ads should be displayed for each member to attract the maximum attention and hits.Police Departments uses predictive analysis to predict when and where crimes were likely to occur, so officers can be on hand to prevent their occurrence

Business Intelligence

Closely linked to the concept of data miningInvolves gathering enough of the right information in a timely manner and usable form and analyzing it so that it can have a positive effect on business strategy, tactics, or operations.Business intelligence turns data into useful information that is then distributed throughout an enterprise.

contCompetitive intelligence is one aspect of business intelligence limited to information about competitors and the ways that knowledge affects strategy, tactics, and operations.Competitive intelligence is not spying. Information should be collected by examining published information sources, conducting interviews, and using other legal, ethical methodsCounterintelligence: The steps an organization takes to protect information sought by hostile intelligence gatherers. E.g trade secrets

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