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Definition
| A named two-dimensional table of data. |
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Term
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Definition
| An attribute or a combination of attributes that uniquely identifies each row in a relation. |
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Definition
| A primary key that consists of more than one attribute. |
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Definition
| An attribute in a relation that serves as a primary key of another relation in the same database. |
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Definition
| A value that may be assigned to a attribute when no other value applies or when the applicable value is unknown. |
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Definition
| A rule that states that no primary key attribute (or component of a primary key attribute) may be null. |
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Term
| Referential Integrity Constraint |
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Definition
| A rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null. |
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Term
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Definition
| A relation that contains minimal redundancy and allows users to insert, modify and delete the rows in a table without error or inconsistencies. |
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Definition
| An error or inconsistency that may result when a user attempts to update a table that contains redundant data. The three types of anomalies are insertion, deletion, and modification anomalies. |
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Definition
| A serial number or other system-assigned primary key for a relation. |
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Definition
| A foreign key in a relation that references the primary key values of the same relation. |
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Term
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Definition
| The process of decomposing relations with anomalies to produce smaller, well-structured relations. |
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Definition
| A state of a relation that requires that certain rules regarding relationships between attributes (or functional dependencies) are satisfied. |
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Definition
| A constraint between two attributes in which the value of one attribute is determined by the value of another attribute. |
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Term
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Definition
| The attribute on the left side of the arrow in a functional dependancy |
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Term
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Definition
| An attribute, or combination of attributes, that uniquely identifies a row in a relation. |
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Term
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Definition
| A relation that has a primary key and in which there are no repeating groups. |
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Term
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Definition
| A relation in first normal form in which every non-key attribute is fully functionally dependent on the primary key |
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Term
| Partial Functional Dependency |
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Definition
| A functional dependency in which one or more non-key attributes are functionally dependent on part (but not all) of the primary key. |
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Term
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Definition
| A relation that is in second normal form and has no transitive dependencies. |
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Term
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Definition
| Two (or more) attributes that have different names but the same meaning. |
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Term
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Definition
| An alternative name used for an attribute. |
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Term
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Definition
| An attribute that may have more than one meaning |
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Term
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Definition
| A functional dependency between the primary key and one or more non-key attributes that are dependent on the primary key via another non-key attribute. |
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