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Information Systems Today: Managing in the Digital World TB3-1 3 Technology Briefing Database Management Modern organizations are said to be drowning in.

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Presentation on theme: "Information Systems Today: Managing in the Digital World TB3-1 3 Technology Briefing Database Management Modern organizations are said to be drowning in."— Presentation transcript:

1 Information Systems Today: Managing in the Digital World TB3-1 3 Technology Briefing Database Management Modern organizations are said to be drowning in data but starving for information p. 509 COIS11011 WEEK 11

2 Information Systems Today: Managing in the Digital World TB3-2 Learning Objectives

3 Information Systems Today: Managing in the Digital World TB3-3 Learning Objectives

4 Information Systems Today: Managing in the Digital World TB3-4 Database Management for Strategic Advantage Database technology is vital to an organizations success Variety of information collected and stored o Stock prices o Potential customers o Credit ratings of wholesalers o Etc.

5 Information Systems Today: Managing in the Digital World TB3-5 Database Management for Strategic Advantage (II) Database technology used for: o Gathering and storing customer information o Custom-tailoring catalogs and mailings o Fueling electronic commerce o Etc.

6 Information Systems Today: Managing in the Digital World TB3-6 Learning Objectives

7 Information Systems Today: Managing in the Digital World TB3-7 Database Foundations Then: o Card catalogs o File cabinets Now: o DBMS Create Store Organize Retrieve data o E.g., Microsoft Access

8 Information Systems Today: Managing in the Digital World TB3-8 Database o Collection of related data organized in a way to facilitate searches o Entities Something you collect data about E.g.: people, books

9 Information Systems Today: Managing in the Digital World TB3-9 Record Contains data about a single entity o Similar to catalog card

10 Information Systems Today: Managing in the Digital World TB3-10 Attributes Specific characteristic describing the entities o E.g.: name and social security number are attributes of a person

11 Information Systems Today: Managing in the Digital World TB3-11 Example: Entity Student Entity represented as a table, with rows as records and columns as attributes

12 Information Systems Today: Managing in the Digital World TB3-12 Advantages of the Database Approach 1. Program-data independence 2. Minimal data redundancy 3. Improved data consistency 4. Improved data sharing 5. Increased productivity of application development

13 Information Systems Today: Managing in the Digital World TB3-13 Advantages of the Database Approach (II) 6. Enforcement of standards 7. Improved data quality 8. Improved data accessibility 9. Reduced program maintenance

14 Information Systems Today: Managing in the Digital World TB3-14 Cost and Risks of the Database Approach 1. New, specialized personnel 2. Installation and management cost and complexity 3. Conversion costs 4. Need for explicit backup and recovery 5. Organizational conflict

15 Information Systems Today: Managing in the Digital World TB3-15 Effective Management of Databases Database Administrator (DBA) o Responsible for development and management of databases Works with system analysts and programmers Works with users and managers Implements security features Grants access rights o One of the key actors in creating a successful database

16 Information Systems Today: Managing in the Digital World TB3-16 Entering Data Forms o Enter data about a record o Field in a form corresponds to attribute in a record o Used to add, modify, or delete data

17 Information Systems Today: Managing in the Digital World TB3-17 Example: Computer-Based Form

18 Information Systems Today: Managing in the Digital World TB3-18 Querying Data Query: used to retrieve information Structured Query Language (SQL) o Example: Display students who earned an A o Writing SQL queries can become very complex

19 Information Systems Today: Managing in the Digital World TB3-19 Query by Example Simpler than SQL Drag-and- drop features Construct a sample of the data we would like to see

20 Information Systems Today: Managing in the Digital World TB3-20 Creating Database Reports Report o Compilation of data from the database Report generators o Retrieve, manipulate, and display data Example o Quarterly sales for a restaurant Adding Grouping

21 Information Systems Today: Managing in the Digital World TB3-21 Database Design Data need to be organized for retrieval and analysis o Key elements of a database Data Structure Data model o A map or a diagram representing entities and their relationships

22 Information Systems Today: Managing in the Digital World TB3-22 Example: Entities and Their Attributes

23 Information Systems Today: Managing in the Digital World TB3-23 Identifying Records Uniquely identifying records: o Primary Key Unique identifier E.g.: Student ID number, social security number o Combination primary key Combination of two or more attributes E.g.: identifying a students grade for a particular class for a particular term Identifying records that share a common value o Secondary Key Attribute not used as a primary key E.g., Major

24 Information Systems Today: Managing in the Digital World TB3-24 Associations Used to relate information between tables Needed to retrieve information Example: Basketball league database

25 Information Systems Today: Managing in the Digital World TB3-25 Example: Basketball League Each table contains important data No way to learn which team plays in a specific stadium Need to make associations

26 Information Systems Today: Managing in the Digital World TB3-26 Example: Basketball League Foreign keys o Attributes used to link tables o Primary key in one table, foreign key in another o Need to create additional entity for many-to-many relationships

27 Information Systems Today: Managing in the Digital World TB3-27 Entity-Relationship Diagram Used to show associations between entities Important when designing complex databases o Entities: represented by boxes o Relationships: represented by lines Associations

28 Information Systems Today: Managing in the Digital World TB3-28 The Relational Model Primary DBMS approach (RDBMS) 3 dimensions o Entities represented as 2-dimensional tables Rows = records Columns = attributes o Tables joined based on common columns (3 rd dimension) Good design eliminates redundancy

29 Information Systems Today: Managing in the Digital World TB3-29 Data Redundancy Problematic if an attribute has to be changed o Need to change in multiple locations E.g., instructors phone number

30 Information Systems Today: Managing in the Digital World TB3-30 Normalization Eliminate unnecessary redundancy o Create separate tables o Data only needs to be changed in a single location

31 Information Systems Today: Managing in the Digital World TB3-31 Data Dictionary Document that specifies what data needs to be entered o Attribute name o Key or not o Data type o Valid values Can be used to enforce business rules

32 Information Systems Today: Managing in the Digital World TB3-32 Linking Website Applications to Organizational Databases Users can access a variety of data via a companys web site o Web services help in integration of databases, regardless of physical location Need for adequate systems performance Get understanding of customer behavior


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