Second Normal Form (2NF)

2NF predicates that in a relation \(R\), there is no (non-prime) attribute \(A\) such that, * \(c \to A\) , such that \(c \subset C\) , where C is a candidate key * It means that each attribute is dependent on the whole candidate key

Consider the following schema Lot - (property_ID, , lot_area, base_price, tax_rate)

Here are the functional dependencies property_ID -> lot, lot_area, state lot, lot_area -> base_price state -> tax_rate

State, lot is a candidate key. But tax_rate is only dependent on a part of this candidate key, so we will move it to a new table. Lot - (property_ID, , lot_area, base_price) Tax - (state, tax_rate)

This schema in 2NF now.