330 likes | 669 Views
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.
E N D
Chapter 3Database 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 theMost 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