| A | B |
|---|
| Secondary UID | An alternate unique identifier for an entity, when there is more than one UID available |
| Mutually exclusive relationship | A relationship that has choices that are unable to be true at the same time. |
| Third Normal Form or 3NF | The form of database normalization where all non-key fields are dependent on the key, the whole key and nothing but the key. |
| Simple UID | A unique identifier that is composed of one attribute. |
| Artificial UID | A unique identifier that does not occur in nature. |
| Hierarchical relationship | A series of relationships that reflect entities organized into successive levels. |
| Transitive dependency | A condition that exists when any attribute in an entity is dependent upon any other non-UID attribute in that entity. |
| Composite UID | A unique identifier that is a combination of attributes and/or relationships. |
| Primary UID | The designated unique identifier for an entity, when there is more than one UID available. |
| Unique identifier (UID) | Any combination of attributes and/or relationships that serves, in all cases, to uniquely identify an occurrence of an entity. |
| Second Normal Form or 2NF | The output of the second step of database normalization. |
| Artificial attribute | A created attribute that does not occur in nature. |
