Chapter 4. Data Management
by ZHI JIE SIM
1. The Hierarchy of Data
1.1. Data type
1.1.1. Hyperlink
1.1.2. Date
1.1.3. Memo
1.1.4. Auto number
1.1.5. Text
1.1.6. Numeric
1.2. Maintain by
1.2.1. Secondary key
1.2.2. Foreign key
1.2.3. Candidate key
1.2.4. Primary Key
1.3. character (cells)
1.4. field (columns)
1.5. record (rows)
1.6. files
2. File Processing Versus Databases Processing
2.1. File processing system
2.1.1. •Each department has its own set of files
2.1.2. •Used for many years
2.1.3. •data redundancy
2.1.4. •Isolate data
2.2. Database approach
2.2.1. •Programs and users share data
2.2.2. •Reduce data redundancy
2.2.3. •Improve data integrity
2.2.4. •Allows easier access
2.2.5. •Reduces development time
2.2.6. •Can be more vulnerable
3. Databases, Data, and Information
3.1. Database
3.1.1. Collection of data organized in a manner that allows access, retrieval, and use of that data
3.2. Data
3.2.1. Collection of unprocessed items -Text,Numbers,Images,Audio,Video
3.3. Information
3.3.1. Processed data -Documents,Audio,Images,Video