Types of Databases

Types of Databases

1. Flat Databases

   • A flat database consists of one table holding every piece of information there is to know for that database
   • Able to make errors and lack of update
   • Takes a long time
   • Advantages and disadvantages
     • Time consuming
     • Enables more errors
     • Can't give different people different amounts of access

2. Relational Databases

   • A database which consists of multiple tables ranging with a lot of different aspects of the data, which all link together and contribute to what the total will be
   • This enables less mistakes as there are often numbers for each aspects of the data, meaning when one piece of data is changed it is simpler in the fact that only one piece of information needs to be changed requiring less time.
   • Quicker and simpler with less complication and needing to change less features and quicker due to this aspect as well.
   • Advantages and disadvantages
     • Easier to give different people different amounts of data
     • Easily be linked with other information
     • Errors could still be made
   • Features
     • Information separated into discrete Entities
       • Based on real world
       • E.g. Employee, 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 a common field
         • Represented by entity relationship diagrams (ERDs)

3. Local Databases

   • A one user network or computer, in which only that one person can access any information or enable any editing of the information
   • When personal information such as finances, e.g. wages are dealt with they're dealt with on a local database so that only that one person can access it

4. Networked databases

   • This form of database is available and can be accessed by anyone with an account for that database.
   • This form of database has a lot more limitations to the availability of viewing of information than for instance a local database does and that is because its a wider and larger database, holding more information.
   • Within larger networks there is a bigger network used where any account can be accessed on any device involved in the database with a username and password

5. Online Databases

   • Examples
     • Larger companies
       • Companies which can be accessed online and at home with the use of a username and password.
     • Supermarkets: Asda, Tesco & Sainsbury's
     • Regular Shops
     • Online stores
       • Ebay
       • Amazon
   • Why are they used?
     • These forms of databases are used to make these types of database accessible and available to a wide range of users
     • Online shopping avaliable
     • Updates availability and stock constantly, especially for account owners