Functionally Determined and 1NF

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In summary, "Functionally Determined" in the context of 1NF means that every attribute in a relation is functionally dependent on the primary key. This concept also applies to other normal forms, but with additional conditions. It is important for a relation to be "Functionally Determined" in 1NF to maintain data integrity and efficiency. A relation cannot be in 1NF without being "Functionally Determined" and this can be ensured by carefully designing the database schema and establishing proper relationships between entities.
  • #1
WWGD
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Hi All,
Say we have a relation R ( i.e., a table in a relational DB ), which has a primary key PK, but R is not

in 1 NF. I guess we then conclude that PK _does not_ functionally-determine the table, since, after

the table is put in 1NF, PK is o longer the primary key, right? It seems obviously true, but I have

been wrong before...

Thanks.
 
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It might help to say that "1 NF" means First Normal Form.
 

Related to Functionally Determined and 1NF

1. What does "Functionally Determined" mean in the context of 1NF?

In 1NF (First Normal Form), "Functionally Determined" means that every attribute in a relation is functionally dependent on the primary key. This means that the value of each attribute can be uniquely determined by the primary key.

2. How does "Functionally Determined" differ from other normal forms?

In other normal forms, such as 2NF and 3NF, the concept of "Functionally Determined" still applies, but additional conditions are also required. For example, in 2NF, every non-prime attribute must be functionally dependent on the entire primary key, not just a part of it.

3. Why is it important for a relation to be "Functionally Determined" in 1NF?

In 1NF, it is important for a relation to be "Functionally Determined" because it ensures data integrity and avoids data redundancy. It also allows for efficient querying and manipulation of the data.

4. Can a relation be in 1NF without being "Functionally Determined"?

No, in order for a relation to be in 1NF, it must also be "Functionally Determined". This is a fundamental requirement of 1NF and cannot be compromised.

5. How can we ensure that a relation is "Functionally Determined" in 1NF?

To ensure that a relation is "Functionally Determined" in 1NF, we must carefully design the database schema and establish proper relationships between entities. This involves identifying and defining the primary key and ensuring that every attribute is functionally dependent on it.

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