3-1 Chapter 3 Data and Knowledge Management

Information Systems Today (©2006 Prentice Hall) 3-2 Learning Objectives 1.Describe why databases have become so important to organizations 2.Describe what databases and database management systems are and how they work

Information Systems Today (©2006 Prentice Hall) 3-3 Learning Objectives 3.Explain how organizations are getting the most from their investment in database technologies 4.Describe what is meant by knowledge management and knowledge assets as well as benefits and challenges of deploying a knowledge management system

Information Systems Today (©2006 Prentice Hall) 3-4 Database Technology A collection of related data organized in a way that makes it valuable and useful Allows organizations to retrieve, store, and analyze information easily Is vital to an organization’s success in running operations and making decisions

Information Systems Today (©2006 Prentice Hall) 3-5 Database Terminology Entities Things we store information about. (i.e. persons, places, objects, events, etc.) Have relationships to other entities (i.e. the entity Student has a relationship to the entity Grades in a University Student database Attributes These are pieces of information about an entity (i.e. Student ID, Name, etc. for the entity Student)

Information Systems Today (©2006 Prentice Hall) 3-6 Relationship of DBMS Concepts to Others?

Information Systems Today (©2006 Prentice Hall) 3-7 Levels of a Database Management System (DBMS) Database Record File Field Individual characteristics about an ENTITY. Fields are also called attributes or columns depending on the type of DBMS Term A group of fields or attributes to describe a single instance of an ENTITY. These are also called rows depending on the DBMS A collection of records or instances for a given ENTITY. These are also called tables depending on the DBMS A collection of files or entities containing information to support a given system or a particular topic area Term Definitions Lowest Highest Level

Information Systems Today (©2006 Prentice Hall) 3-8 View of a Database Table or File Attribute (One Column) Record (One Row) Attribute Type

Information Systems Today (©2006 Prentice Hall) 3-9 File Processing vs Database Approach Summary File Processing Approach (Old School) Storage Media: Sequential tapes or files Data: stored in long sequential files Organization: redundant data in multiple files Efficiency: data embedded to support processing Updates: requires multiple updates in many files Processing: slower query/faster processing Data Base Approach (New School-TODAY) Storage Media: Direct Access Storage Device (DASD) Data: stored in related tables Organization: redundant data minimized/eliminated Efficiency: data only stored only in tables Updates: requires few or one update for a data field Processing: faster query/slower processing

Information Systems Today (©2006 Prentice Hall) 3-10 Advantages of the Database Approach

Information Systems Today (©2006 Prentice Hall) 3-11 Costs or Risks of the Database Approach

Information Systems Today (©2006 Prentice Hall) 3-12 Roles in Database Development and Use Database Administrator (DBA) Designs, develops and monitors performance of databases Enforces policy and standards for data uses and security Database Administrator (DBA) Designs, develops and monitors performance of databases Enforces policy and standards for data uses and security Systems Programmer Creates business applications that connect to databases Tests the new systems and databases before use Systems Programmer Creates business applications that connect to databases Tests the new systems and databases before use Systems Analyst Defines data requirements working with a DBA Incorporates the database design into new program designs Systems Analyst Defines data requirements working with a DBA Incorporates the database design into new program designs

Information Systems Today (©2006 Prentice Hall) 3-13 Database Systems Activities – Data Entry Enter Forms Employment Applications (Form Entry Screen)(Form Entry Program)(Employment DB) Example Data is entered from paper employment applications into a form entry screen The entry forms are designed to match the paper forms for easy entry The form data is processed by the entry program and then stored in the employment database

Information Systems Today (©2006 Prentice Hall) 3-14 Database Systems Activities – Query (Query Request)(Query Program)(Employment Query) SQL (Structure Query Language) A language to select and extract data from a database The industry standard language for relational databases QBE (Query by Example) A technique that allows a user to design a query on a screen by dragging and placing the query field in their desired locations Query – A database function that extracts and displays information from a database given selection parameters. Example – Display applicants entered in the last 30 days Query parameters are selected in the query request screen The database program uses SQL to query and present the result

Information Systems Today (©2006 Prentice Hall) 3-15 Database Systems Activities – Report (Query Request)(Query Program)(Employment Report) Report Generator A specialized program that uses SQL to retrieve and manipulate data (aggregate, transform, or group) Reports are designed using standard templates or can be custom generated to meet informational needs Report – A database function that extracts and formats information from a database for printing and presentation Example – Report on applicants entered in the last 30 days Report parameters are selected in the report request screen The database program uses SQL to query and present the result

Information Systems Today (©2006 Prentice Hall) 3-16 Designing Databases – Data Model Example: ERD (Entity Relationship Diagram) Data Model A map or diagram that represents entities and their relationships Used by Database Administrators to design tables with their corresponding associations

Information Systems Today (©2006 Prentice Hall) 3-17 Designing Databases – Keys Primary Key A unique attribute type used to identify a single instance of an entity. Secondary Key An attribute that can be used to identify one or more records within a table with a given value Compound Primary Key A unique combination of attributes types used to identify a single instance of an entity Database Keys Mechanisms used to identify, select, and maintain one or more records using an application program, query, or report

Information Systems Today (©2006 Prentice Hall) 3-18 Designing Databases – Keys (Example) Primary Key - Student ID ENTITIES Compound Primary Key - Student ID - Course ID - Sec No. - Term Secondary Key - Major Entities are translated into Tables (Students and Grades) Entities are joined by common attributes

Information Systems Today (©2006 Prentice Hall) 3-19 Designing Databases - Associations Associations Define the relationships one entity has to another Determine necessary key structures to access data Come in three relationship types: - One-to-One - One-to-Many - Many-to-Many Foreign Key An attribute that appears as a non-primary key in one entity (table) and as a primary key attribute in another entity (table)

Information Systems Today (©2006 Prentice Hall) 3-20 Designing Databases - Associations Entity Relationship Diagram (ERD) Diagramming tool used to express entity relationships Very useful in developing complex databases Example Each Home Stadium has a Team (One-to-One) Each Team has Players (One-to-Many) Each Team Participates in Games For each Player and Game there are Game Statistics

Information Systems Today (©2006 Prentice Hall) 3-21 Designing Databases - Associations

Information Systems Today (©2006 Prentice Hall) 3-22 Designing Databases – Associations (Example)

Information Systems Today (©2006 Prentice Hall) 3-23 The Relational Model The most common type of database model used today in organizations Is a three-dimensional model compared to the traditional two-dimensional database models - Rows (first-dimension) - Columns (second-dimension) - Relationships (third-dimension) The third-dimension makes this model so powerful because any row of data can be related to any other row or rows of data

Information Systems Today (©2006 Prentice Hall) 3-24 The Relational Model - Example

Information Systems Today (©2006 Prentice Hall) 3-25 The Relational Model - Normalization Normalization A technique to make complex databases more efficient by eliminating as much redundant data as possible Example: Database with redundant data (below)

Information Systems Today (©2006 Prentice Hall) 3-26 The Relational Model - Normalization Normalized Database

Information Systems Today (©2006 Prentice Hall) 3-27 The Relational Model – Data Dictionary Data Dictionary Is a document that database designers prepare to help individuals enter data Provides several pieces of information about each attribute in the database including: - Name - Key (is it a key or part of a key) - Data Type (date, alpha-numeric, numeric, etc.) - Valid Value (the format or numbers allowed) Can be used to enforce Business Rules which are captured by the database designer to prevent illegal or illogical values from entering the database. (e.g. who has authority to enter certain kinds of data) Data Dictionary Is a document that database designers prepare to help individuals enter data Provides several pieces of information about each attribute in the database including: - Name - Key (is it a key or part of a key) - Data Type (date, alpha-numeric, numeric, etc.) - Valid Value (the format or numbers allowed) Can be used to enforce Business Rules which are captured by the database designer to prevent illegal or illogical values from entering the database. (e.g. who has authority to enter certain kinds of data)

Information Systems Today (©2006 Prentice Hall) 3-28 Online Transactional Processing (OLTP) Online Transactional Processing The mechanism by which customers, suppliers, and employees process business transactions for an organization These users conduct transactions online through internal systems and external Websites for processing and storage Example

Information Systems Today (©2006 Prentice Hall) 3-29 Operational vs Informational Systems

Information Systems Today (©2006 Prentice Hall) 3-30 Organizational Use of Databases Department Databases Data Warehouse Data Mart OperationalInformational Extract Data Extract Data Extract Data Extract Data Day to Day Department Transactions Used primarily by departments Extracted Department transactions Used for business analysis Extracted subset of a data warehouse Used for highly specific business analysis

Information Systems Today (©2006 Prentice Hall) 3-31 Online Analytical Processing (OLAP) Online Analytical Processing Graphical software tools that provide complex analysis of data stored on a database OLAP tools enable users to analyze different dimensions of data beyond data summary and data aggregations of normal database queries The OLAP Server is the chief component of an OLAP system which understands how the data is organized and has special functions for analyzing data OLAP can provide time series and trend analysis views of data, data-drill downs, and the ability to answer “what-if” and “why” questions as part of its functions

Information Systems Today (©2006 Prentice Hall) 3-32 Data Mining Is a method companies use to analyze information to better understand their customers, products, markets, or any other phase of their business for which they have data With data mining tools you can graphically drill down, sort or extract data based on certain conditions, perform a variety of statistical analysis Data mining applications are very powerful and use highly complex algorithms to analyze and to identify opportunities

Information Systems Today (©2006 Prentice Hall) 3-33 Data Warehouse Example

Information Systems Today (©2006 Prentice Hall) 3-34 Uses of Data Warehousing

Information Systems Today (©2006 Prentice Hall) 3-35 Knowledge Management Definitions Knowledge Assets All underlying skills routines, practices, principles, formulas, methods, heuristics, and intuitions whether explicit or tacit Tacit Knowledge The processes and procedures on how to effectively perform a particular task stored in a persons mind Explicit Knowledge Anything that can be documented, archived, or codified often with the help of information systems Knowledge Management The process an organization uses to gain the greatest value from its knowledge assets

Information Systems Today (©2006 Prentice Hall) 3-36 Knowledge Management System (KMS) Primary Objective How to recognize, generate, store, share, manage this tacit knowledge (Best Practices) for deployment and use Technology Generally not a single technology but instead a collection of tools that include communication technologies (e.g. , groupware, instant messaging), and information storage and retrieval systems (e.g. database management system) to meet the Primary Objective Best Practices Procedures and processes that are widely accepted as being among the most effective and/or efficient

Information Systems Today (©2006 Prentice Hall) 3-37 Benefits and Challenges of Knowledge Management