Given a relation R (in a relational database), attribute Y of R is functionally dependent on attribute X of R and X of R functionally determines Y of R (in symbols R.X -> R.Y) if and only if each X in R has associated with it precisely one Y in R (at any one time). Attributes X and Y may be composite.
This is very close to a function in the mathematical sense.
noun, Pathology. 1. a disease in which there is an abnormal change in the function of an organ, but no structural alteration in the tissues involved (opposed to ). noun 1. a disease in which there is no observable change in the structure of an organ or part Compare organic disease
- Functional disorder
functional disorder n. A physical disorder in which the symptoms have no known or detectable organic basis but are believed to be the result of psychological factors such as emotional conflicts or stress. Also called functional disease.
- Functional food
noun 1. a food containing additives which provide extra nutritional value Also called nutraceutical noun any foodstuff enhanced by additives and marketed as beneficial to health and longevity; also called nutraceutical Word Origin from Japanese kinsei-shokuhin ‘functionality’ ‘food’ Usage Note abbr. FF
noun 1. a group of atoms responsible for the characteristic behavior of the class of compounds in which the group occurs, as the hydroxyl group in alcohols. noun 1. (chem) the group of atoms in a compound, such as the hydroxyl group in an alcohol, that determines the chemical behaviour of the compound functional group […]