Element of a good table (Ref: Database design mere mortals by Michael J. Hernandez)

 Elements of the Ideal Table:

1. It represents a single subject, which can be an object or event that reduces the risk of potential data integrity problems.

2. It has a primary key. This is important for two reasons: A primary key uniquely identifies each record within a table, and it plays a key role (no pun intended) in establishing table relationships.

3. It does not contain multipart or multi-valued fields.

4. It does not contain calculated fields.

Ex:

Table orders:

id	unit_price	quantity	total_amount
1	10	5	50
2	5	2	10

This is bad table design.

 Problems:

1. Redundancy → total_amount = unit_price * quantity is stored unnecessarily.

2. Inconsistency risk → If quantity is updated but total_amount isn’t recalculated, the data becomes wrong.

3. Extra storage → You’re saving the same information twice (derived + original).

Solution:

id	unit_price	quantity
1	10	5
2	5	2

5. It does not contain unnecessary duplicate fields.

6.It contains only an absolute minimum amount of redundant data.