Term
|
Definition
| Process for evaluating and correcting table structures to reduce data anomalies, redundancies, and inconsistencies |
|
|
Term
|
Definition
First Normal Form
Second Normal Form
Third Normal Form
BCNF
Fourth Normal Form
Fifth Normal Form
Domain Key Normal Form |
|
|
Term
|
Definition
| The slower the database response |
|
|
Term
|
Definition
Data inconsistencies
Wasted data entry time and storage space |
|
|
Term
|
Definition
| Abnormal data relationships |
|
|
Term
|
Definition
Insert anomaly
Update anomaly
Deletion anomaly |
|
|
Term
| Main source of data anomalies |
|
Definition
|
|
Term
|
Definition
Start with a big table
Break into a set of smaller tables that are related
Each table represents a single entity to eliminate data redundancies |
|
|
Term
|
Definition
Groups of multiple entries of the same type that exist for any single key attribute occurrence
Cause null values |
|
|
Term
|
Definition
No repeating groups, and the primary key is identified
Enter in values for all of the null values, then identify a primary key
Primary key can't have redundancies and must be an identifier of other columns
Draw a dependency diagram |
|
|
Term
|
Definition
| An attribute depends on only a portion of the primary key |
|
|
Term
|
Definition
Two none key attributes that depend on each other
Cause data anomalies |
|
|
Term
| How to convert table from 1NF to 2NF |
|
Definition
| Eliminate partial dependencies |
|
|
Term
| How to convert table from 2NF to 3NF |
|
Definition
| Eliminate transitive dependencies |
|
|
Term
| How to remove partial dependencies |
|
Definition
Write each key component of a separate line
Write composite key on the last line
Assign dependent attributes |
|
|
Term
| Table is already in 2NF when |
|
Definition
It is in 1NF
and includes no partial dependencies so the table has a single primary key |
|
|
Term
| When you remove a transitive dependency... |
|
Definition
| keep the determinant in the original table, otherwise you will lose that link |
|
|
Term
|
Definition
| Every determinant in table is a candidate key |
|
|
Term
|
Definition
It is is 2NF
And no multiple set of multi-valued dependencies |
|
|
Term
|
Definition
| Go from 3rd form to 2nd form to save time on queeries |
|
|
