Greenville, South Carolina. For other uses, see Greenville. Greenville (/ËÉ¡riËnvÉªl/; locally /ËÉ¡riËnvÉl/) is the county seat of Greenville County in the upstate region of South Carolina, in the United States. The city's mayor is Knox White, who has served in that position since December 1995.
Non-key Attributes. back: surrogate key. next: derived attributes. Non-key attributes are attributes that are not part of a key. Generally, most attributes are simply descriptive, and fall into this category. Consider attributes for first name, last name, birth date; usually these attributes are non-key attributes.Consider a name attribute.on-key Attributes. back: surrogate key. next: derived attributes. Non-key attributes are attributes that are not part of a key. Generally, most attributes are simply descriptive, and fall into this category. Consider attributes for first name, last name, birth date; usually these attributes are non-key attributes.
In database relational modeling and implementation, a unique key is a set of zero, one, or more attributes. The value(s) of these attributes are required to be unique for each tuple (row) in a relation.The value, or combination of values, of unique key attributes for any tuple should not be repeated for any other tuple in that relation.he value(s) of these attributes are required to be unique for each tuple (row) in a relation. The value, or combination of values, of unique key attributes for any tuple should not be repeated for any other tuple in that relation.