Normalizing data within a database could include all or some of the following except which one?
A.
Eliminate duplicative columns from the same table.
B.
Eliminates functional dependencies on a partial key by putting the fields in a separate table from those that
are dependent on the whole key
C.
Eliminates Functional dependencies on non-key fields by putting them in a separate table. At this level, all
non-key fields are dependent on the primary key.
D.
Eliminating duplicate key fields by putting them into separate tables.
Explanation:
Normalizing data within a database does not eliminate duplicate key fields by putting them into separate tables.
An entity is in First Normal Form (1NF) when all tables are two-dimensional with no repeating groups.
A row is in first normal form (1NF) if all underlying domains contain atomic values only. 1NF eliminates
repeating groups by putting each into a separate table and connecting them with a one-to-many relationship.
Make a separate table for each set of related attributes and uniquely identify each record with a primary key.
Eliminate duplicative columns from the same table.
Create separate tables for each group of related data and identify each row with a unique column or set of
columns (the primary key).
An entity is in Second Normal Form (2NF) when it meets the requirement of being in First Normal Form (1NF)
and additionally:
Does not have a composite primary key. Meaning that the primary key cannot be subdivided into separate
logical entities.
All the non-key columns are functionally dependent on the entire primary key.
A row is in second normal form if, and only if, it is in first normal form and every non-key attribute is fullydependent on the key.
2NF eliminates functional dependencies on a partial key by putting the fields in a separate table from those
that are dependent on the whole key. An example is resolving many:many relationships using an
intersecting entity
An entity is in Third Normal Form (3NF) when it meets the requirement of being in Second Normal Form (2NF)
and additionally:
Functional dependencies on non-key fields are eliminated by putting them in a separate table. At this level,
all non-key fields are dependent on the primary key.
A row is in third normal form if and only if it is in second normal form and if attributes that do not contribute
to a description of the primary key are move into a separate table. An example is creating look-up tables.
Incorrect Answers:
A: Normalizing data within a database does eliminate duplicative columns from the same table.
B: Normalizing data within a database does eliminate functional dependencies on a partial key by putting the
fields in a separate table from those that are dependent on the whole key.
C: Normalizing data within a database does eliminate Functional dependencies on non-key fields by putting
them in a separate table.http://psoug.org/reference/normalization.html
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