A collection of persistent data that can be shared and interrelated. A system or application that must be operational for a company to function.

Transcription

1 Objec.ve Introduc.on to Databases Dr. Jeff Pi9ges ITEC 0 Provide an overview of database systems What is a database? Why are databases important? What careers are available in the Database field? How do I learn more about databases? 2 What is a Database? A collection of persistent data that can be shared and interrelated What is a Mission Critical System or Application? A system or application that must be operational for a company to function. Mannino, Database Design, Application Development, & Administration, 3rd Edition 3 4 Examples of Mission Critical Systems Mission Critical Business system that does not require a database Point of Sale Order Processing Warehouse Management Systems Financial Systems 5 6

2 : Database Container Oracle Corporation Database Database Database 7 8 Why Databases? " In the Beginning omer 9" 0 Program-Data Dependence System Model DATA DIVISION. FILE SECTION. FD EMP-FILE LABEL RECORDS ARE OMITTED. 0 EMP-RECORD. 05 EMP-NUMBER PIC 9(4). 05 EMP-LASTNAME PIC (). 05 EMP-FIRSTNAME PIC (). 05 EMP-SE PIC (). 05 EMP-DEPTID PIC (4). 05 EMP-SALARY PIC 9(8). 2 2

3 Problems with System Model The Solution: Changes to file structure or file location effect many programs causing high maintenance costs. Data in various and sometimes proprietary data formats. Indexes were easily corrupted if not open during data entry, updates, or deletes. All Data validation was completely dependent on all application programs. All Data security was completely dependent on all application programs. Efficient Multi-application / multi-user access to the same file(s) required strict adherence to agreed upon locking strategies. Integrated backup and recovery of hundreds of data files is difficult to control. Tendency for redundant data to enter various data files. 3 Changes to file structure or file location are transparent to application programs. Maintenance costs drop dramatically. 4 The Solution: The Solution: Q & R tools Constraints All data is available through a standard interface and related, industry standard query and reporting tools. All Data validation rules are defined within the and enforced independently of application program logic. 5 6 The Solution: The Solution: Users Grants Locks Rollbacks Commits Transactions Primary responsibility for Data security is now handled by the providing user based security down to the attribute level. 7 All aspects of multi-user access are handled by the. 8 3

4 The Solution: Backup Recovery Recovery Log s The Solution: Schema DBA A comprehensive, integrated solution to backup and recovery is provided. 9 A single normalized conceptual model of all data managed by a database administrator (DBA) eliminating redundant and therefore inconsistent data. 20 Relational Model Relational model is based on tables with rows and columns Intuitive R is based on extensive theory Relational Algebra Commercial database vendors have implemented a subset of the relational model, often with proprietary extensions Relations and Tuples Employees Table EMPID LNAME FNAME SE DEPT PHONE SALARY 23 Jones Mark M ITR Smith Sara F FINC Billings David M ACTG Dance Ivanna F ACTG Jones Mary F ITR Barker Bob M ACTG Woods Robin M ITR Jones Mary F FINC Challenges Databases are conceptually simple Databases and Opera.ng Systems are large, mul.- user systems that face nearly every major challenge of compu.ng systems Database Jobs. Database Developer 2. Database Administrator (DBA) 3. Data / Business Analyst Many students report that databases are far more interes.ng and challenging than expected

5 Database Developer Develop informa.on systems and database applica.ons Database engineers work exclusively within the database SoYware engineers may design and develop end- to- end systems Concentra.ons and Cer.fica.ons Database SoYware Engineering Web Development Security Cer.ficate Database Development Query the database using Data Modeling Design and develop physical database objects Design transac.ons Develop stored procedures and triggers : Structured Query Language Specify data to be retrieved from the database SELECT name, gpa FROM Students WHERE rank = SR AND major = ITEC ORDER BY gpa DESC First City Find a Friend on Facebook Last State School SELECT first, last, city, state, school FROM Users WHERE first =? AND last =? AND school =? AND city =? AND state =?; Data Modeling Conceptual representa.on of how data is organized in the database En.ty Rela.onship Diagrams are similar to object- oriented data models An en.ty usually represents a person, place, or thing

6 Application Schema A standard Oracle application typically starts with pre-defined tables Views Database tables are created to store data efficiently and effec.vely NOT user friendly Views are created on top of the tables Views increase usability by simplifying the schema and crea.ng objects that are meaningful to business users Views enforce security by restric.ng access to rows and columns 3 32 Three Schema Architecture Database Administrator (DBA) View View 2 View n External Level Install and maintain database systems Design and implement database security Manage user accounts and permissions Conceptual Schema Logical Level Backup and recover data Tune and op.mize performance Internal Schema Physical Level Concentra.ons and Cer.ficates Database Security Cer.ficate Physical Design Database developers and analysts work with the conceptual database Database Administrators work with the physical database Data files Disk storage Servers and other hardware

7 24/7 Up.me Enterprise database systems are usually available 24 hours a day, 7 days a week Data Analyst Analyze data to help people and organiza.ons make be9er decisions This requires fault tolerant systems Redundant components Redundant data storage The DBA must recover from failure Concentra.ons and Cer.ficates Database Computer Science Informa.on Systems Going Global The following slides were presented by Paul Grossman at the February 2009 NCTC Technology & Toast ExportVirginia.org THE REAL WORLD POPULATION THE REAL WORLD CONTAINER PORTS Source: mapper.org 4 Source: mapper.org 42 7

8 THE REAL WORLD HIGH TECH EPORTS990 THE REAL WORLD HIGH TECH EPORTS 2002 Source: mapper.org 43 Source: mapper.org 44 THE REAL WORLD HIGH TECH EPORTS 2002 What If You could view your business like these maps of the world? You could identify trends and compare your business to your competitors with respect to the market? You could see opportunities? Source: mapper.org Business Intelligence A set of tools and techniques that help people and companies make better decisions BI Technologies Data Warehousing OLAP Executive Dashboards Data Mining Decision Support Systems (DSS) Expert Systems

9 Drowning in Data Starving for Information Data Warehousing 49 Data Information Assets 50 Warehouses Report the Facts Who What When Where Why OnLine Analytical Analy.cal Processing The process of slicing and dicing data: Drill Down Drill Up Drill Across OLAP 5 52 OLAP Example estigate the Facts Analyze quarterly sales Expected 0% increase in revenue Realized a 9.5% increase Why did quarterly revenue fall short of expectations? Why were sales short of expectations? When Time Dimension Compare sales in 2005 to 2006 What -- Product Dimension Who -- omer Dimension

10 Dimensional Model Time Day Week Month Quarter Year Weekend Holiday Product Department Category Brand Weight omer Age Gender Status Income Year When Time Dimension Quarter Month Week Day Time Dimension by Quarter $00 $09.5 é 9.5% 2005 Q2 Time Q3 Quarter 05 Q Q What Product Dimension Product Hierarchy Department Category Drill Down into Department Brand - Clothes - Electronics - Books T i m e 2005 Q Q Q 3 Q 4 Q Q 2 Product C l o t h e s E l e c t r o n i c s P r o d u c t B o o k s

11 By Department Drill Down into Books Product Hierarchy 0.3% 0.4% 8.7% 0% Department Category Dept Clothes Electronics Books Brand Product 6 62 Product Dimension by Book Category Novels Textbooks 0.6% 6.8% Time 2005 Q2 Q3 0% 2006 Q4 Category Novels Textbooks Q2 Clothes Electronics Books Product Who Drill Down into Age Group omer Dimension Age group Gender Marital status 4.2% 0.9% 0.4%.% 0% Occupation Age Under Over 65 Annual income 65 66

12 omer Dimension Analysis Over Under omer Novels Textbooks of textbooks to customers under 25 (students) fell well short of expectations What should the company do? Time 2006 Q2 Q3 Q4 Increase advertisements and incentives for textbooks to students Q2 Clothes Electronics Books Product Executive Dashboards Monitoring Your Business Management by Objective (MBO) -- revenue targets omer Support -- customer satisfaction Key Performance Indicators (KPI) Measure performance Dashboard Displays KPIs Color coded Green Yellow Red Example Dashboard Clicking on Virginia drills down to entory by City entory Level Alexandria Richmond Roanoke

13 Data Mining Market Basket Analysis Identify items purchased together Knowledge Discovery Identify patterns in your data Data Mining Tasks Business Intelligence Systems Predict Churn Analysis Increase response rate Estimate omer satisfaction and renewal rate Classify Fraud Detection Enterprise Architecture Database Classes External Data Sources Production Systems Extract Transform Reporting OLAP GUI Data Warehouse Load Data Mining Database I (340) Database Development Database II (44) Database Administra.on Data Warehousing, Mining, Repor.ng (442) Data Analysis