Preventing Data Anomalies

Important

The database development life cycle ooutlines the steps to creating a well considered solution. Shortcutting the process can lead to undesirable results and wasted efforts. Careful consideration can actually protect the database from mistakes and discrepancies.

Removing duplicate infromation

Slow performance

maintenance issues

inconsistencies and anomilies.

Duplicate records should be put into another table.

Relationship Type: One-to-Many :: Attributes: Enforced and Left Join
  1. We remove the column that is not dependent on the main topic of the table and place into the new table.

Remove the dependent column

  1. Then we make the copy of the column that it was dependent on and place that into the table alongside.

Copy the subject column

Relationship Type: One-to-Many :: Attributes: Enforced and Left Join
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