| Term | Definition |
|---|
| Modification Anomaly | An unexpected side effect that occurs when changing the data in a table with excessive redundancies. |
| Insertion Anomaly | Occurs when extra data beyond the desired data must be added to the database. |
| Update Anomaly | Occurs when it is necessary to change multiple rows to modify only a single face. |
| Deletion Anomaly | Occurs whenever deleting a row inadvertently causes other data to be deleted. |
| Functional Dependency | A constraint about two or more columns of a table. X determines Y (X --> Y) if there exists at most one value of Y for every value of X. |
| FDs for 1-M Relationships | assert an FD in the child-to-parent direction of a 1-M relationship. |
| Minimal Determinant | The determinant (column(s) appearing on the LHS of a functional dependency) must not contain extra columns. |
| Normal Form | A rule about allowable dependencies. |
| First Normal Form (1NF) | Prohibits nesting or repeating groups in tables. Tables are nonnormalized. |
| Second Normal Form (2NF) | A table is in this form if each nonkey column depends on all candidate keys, not on a subset of any candidate key. |
| 2NF Violation | An FD in which part of key determines a nonkey. |
| Third Normal Form (3NF) | A table is in this form if it is in 2NF and each nonkey column depends only on candidate keys, not on other nonkey columns. |
| Transitive Dependency | An FD derived by the law of transitivity. Transitive FDs should not be recorded as input to the normalization process. |
| Boyce-Codd Normal Form (BCNF) | A table is in this form if every determinant is a candidate key. |
| Relationship Independence | A relationship that can be derived from two independent relationships. |
Combine with other sets
Share on Facebook
Share on MySpace