In relational algebra, a rename is a unary operation written as where: is a relation and are attribute names is an attribute of The result is identical to except that the attribute in all tuples is renamed to . For an example, consider the following invocation of on an relation and the result of that invocation: Formally, the semantics of the rename operator is defined as follows: where is defined as the tuple , with the attribute renamed to , so that: Relational algebra