Databases

Databases

1. Information rich v Information poor

   • Information rich have access tomlots of types of informatiohn
   • Information poor do not have access to information

2. Types of database

   • Flat file
     • Data can be duplicated
   • Relational
     • Linked to prevent duplication of data

3. Validation types

   • Range check
   • Restricted choice
   • Length check
   • Presence check
   • Unique check

4. Data dictionary

   • This is a plan of the data base

5. Key fields

   • Compound Key
   • Primary Key
   • Foreign Key

Images and files in the map