Types of Databases

Types of Databases

1. Flat Databases

   • One Table used to record all data
   • A disadvantage is that you have to keep typing out the information
   • An advantage is that all of your information is in one place so you don't have to keep looking for different tables

2. Relational Databases

   • More than one table to organise data and link it together
   • E.g. Linking name, address, postcode and phone number of a customer in a table
   • Advantages are that it is simple. Each table is about one thing.
   • Also you only need to change information once so modification can be made with ease
   • Disadvantages are that you could have a lot of tables at one time so may be quite hard to sort through
   • Different levels of access can be given
   • Features
     • Information separated into discrete entities
       • Based on the real world
       • E.g. Employees, Product, Order
     • Entities are described by a series of fields
       • Describes the structure of the entities
       • E.g. Product name, weight, price etc...
     • Entities are connected by a series of relationships
       • Built using common field
       • Represented by entity relationship diagrams(ERDs)

3. Local Databases

   • Only one person will be able to use it at any one time
   • E.g. A finance office
   • Need a username and password
   • Need the right level of access

4. Networked Databases

   • Used for a group of people's information
   • E.g. Employees/Students
   • Need a username and password
   • Need the right level of access

5. Online Databases

   • Supermarket chains such as Tesco, Asda etc...
   • Marketing Companies such as Amazon, Ebay etc...
   • Used to give updated information to viewers
   • Need a username and a password to access them.
   • May be used for online shopping