Programming Exercise I Construction (Cont.)

  1. Oracle 12c Relational Database Design
  2. A properly designed database provides you with access to up-to-date, accurate information. Because a correct design is essential to achieving your goals in working with a database, you are much more likely to end up with a database that meets your needs and can easily accommodate change. The database design process consists of the following steps:

    1. Determine the purpose of your database.
    2. Find and organize the information required.
    3. Divide the information into tables.
    4. Turn information items into columns.
    5. Specify primary keys.
    6. Set up the table relationships.
    7. Refine your design.
    8. Apply the normalization rules.

    Certain principles guide the database design process.

    • The first principle is that duplicate data is bad, because it wastes space and increases the likelihood of errors and inconsistencies.

    • The second principle is that the correctness and completeness of information is important.

    If your database contains incorrect data, any reports that pull data from the database will also contain incorrect data. As a result, any decisions you make that are based on those reports will then be misinformed. Relational database design uses either one of the two methods:

    • Normalization, a series of steps followed to obtain a database design that allows for efficient access and storage of data in a relational database.

    • ER (entity-relationship) modeling, dividing your database in two logical parts, entities (such as “customer” and “product”) and relations (such as “buys” and “pays for”).



      My wife and I have reached the difficult decision that    
      we do not want children. If anybody does,    
      please just send me your contact details and    
      we can drop them off tomorrow.