types of databases

types of databases

1. flat databases

   • one table that includes information about everything
   • data is often repeated within the table
   • you are more likely to make mistakes because there could be hundreds of the same data that you put in

2. relational databases

   • a database that links different sections together.
   • you are less likely to make mistakes as the information is linked and it saves you time inputting it in
   • you can easily change the data. you aren't mixing the data up either.
     • each table is about one thing
   • easier to restrict access to the information
     • different levels of access
   • features
     • information separated into discrete entities
       • based on the real word
         • employee
         • product
         • order
     • described by a series of fields
       • describes the structure of the entity
         • product name
         • weight
         • price
     • connected by a series of relationships
       • built using common fields
       • represented by entity relationship diagrams

3. local databases

   • only one person can use this at a time. for example finance
     • only one persons login will work

4. network databases

   • more than one person can use it. however they need a login, password, plus a level of access that tells them which information they can see or change.

5. online databases

   • examples
     • amazon
     • Tesco
     • ebay
   • why are they used
     • to store information
     • they are updated
     • for companies who need to store information and access them anywhere
       • accessible from internet
   • advantages
     • accessible from anywhere
     • easy to use