3.0 Review
This week we began our project of designing a database for a pharmaceutical chain. We covered a lot of different topics of database design including ER schema, relational schema, relationship cardinalities, and normalization. These are all important concepts that helped us plan, design, and create our database.
3.1 Someone described normalization of a DB design as "a column depends on the key, the whole key, and nothing but the key, so help me Codd." Explain in your words what 3rd normal form is and why it is important.
Normalization is a process in which you try to remove the redundancies of your relation by separating them into separate tables. A relation is in the third normal form if it's in the second normal form and that there is no other non key attribute that you would need to change in a table if you changed a non key attribute. This is important because it reduces the duplication of data and it also keeps the referential integrity.
3.2 What is an SQL view and why is it useful ?
A view is a virtual table based on the result of an SQL statement. It contains rows and columns and the fields are from one or more real tables in the database. this is important because it saves a snapshot of a particular query to which you can then do another query based on this snapshot which can save you a lot of time.
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