Chapter 3 Database Management Information Systems Today Leonard Jessup and Joseph Valacich

Chapter 3 Objectives Understand why databases are important to modern organizations Understand how databases work Understand how organizations can maximize their strategic potential with databases

Database Management for Strategic Advantage Database – a collection of related data organized in a way to facilitate data searches Use databases to: Create a book Track book sales Set salaries and wages Pay employees

Database Management for Strategic Advantage The Database Approach: Foundational Concepts DBMS – Database Management Systems Use a DBMS software to create, store, organize, and retrieve data from a single database or several databases Example: Microsoft Access

Database Management for Strategic Advantage Advantages of the Database Approach Program-data independence Minimal data redundancy Improved data consistency Improved data sharing Increased productivity of application development Enforcement of standards Improved data quality Improved data accessibility Reduced program maintenance

Database Management for Strategic Advantage Effective Management of Databases The database administrator (DBA) : Works with programmers and analysts to design and implement the database Works with users and managers to establish database policies Implements security features and establishes database permissions

Key Database Activities Entering and Querying Data Form Structured Query Language (SQL) Query by example (QBE)

Key Database Activities Creating Database Reports Report – a compilation of data that is organized and produced in printed format Report Generators

Key Database Activities Database Design Must be organized Few or no redundancies Data model – a map of entity relationships Keys Primary key Combination primary key Secondary key

Key Database Activities Database Associations One-to-one (teams to stadiums) One-to-many (player to team) Many-to-many (players to games)

Key Database Activities Entity-Relationship Diagramming (ERD) Commonly used when designing databases One draws entities (tables) as boxes and lines between entities to show relationships

Key Database Activities The Relational Model of Databases Entities linked by a common key field Records = rows Fields = columns Other models exist Hierarchical Network Object-oriented model

Key Database Activities Normalization A technique for making complex databases more efficient and more easily handled by the DBMS Eliminates data redundancy

Key Database Activities Data Dictionary A document that explains each piece of information in the database Field name Data type Numeric, text, date/time Useful for sorting and allocating storage Is this field a key field? Business rules Update authority Valid data values

How Organizations Get the Most from Their Data Linking Web Sites to Databases Example: Amazon 2.5 million titles Managing online data effectively

How Organizations Get the Most from Their Data Data Mining A method for better understanding data Information on customers, products, markets, etc. Drill down: from summary to more detailed data Sort and extract information Trends, correlations, forecasting, statistics

How Organizations Get the Most from Their Data Data Mining Online Transaction Processing (OLTP) Immediate automated responses to user requests Multiple concurrent transactions A big part of interactive Internet e-commerce

How Organizations Get the Most from Their Data Data Mining Online Analytical Processing (OLAP) Graphical software tools that provide complex analysis of data stored in a database Drills down to deeper levels of consolidation Time series and trend analysis “What if” and “why” questions

How Organizations Get the Most from Their Data Data Mining Merging Transaction and Analytical Processing Real-time OLAP diminishes performance because the database must be “locked” during execution time Solution: replicate transactions on a 2nd database server

How Organizations Get the Most from Their Data Data Mining Merging Transaction and Analytical Processing Operational Systems Interact with customers and run a business in real time Examples: Order processing, reservation systems Informational Systems Support decision making based on stable point-in-time or historical data

How Organizations Get the Most from Their Data Data Warehousing Integrating multiple large databases into a single repository Queries, analysis, and processing Purpose: put key business information into the hands of decision makers Cost: millions

How Organizations Get the Most from Their Data Data Marts Instead of one large data warehouse, many organizations create multiple data marts Each contains a subset of the data Example: finance, inventory, personnel Each data mart is customized for particular DSS applications Cost: typically less than $1 million