The data type (data_type) VARCHAR defines an alphanumeric column. Specification of length attribute n is optional. If no other length attribute is specified, then it is assumed that n=1.

VARCHAR [(n)]: 0<n<=8000
VARCHAR [(n)] UNICODE: 0<n<=4000

Use VARCHAR (n) if the values in the column are to be stored with a variable length, irrespective of n.

The data type VARCHAR is specified in the column definition, with a code attribute, if required.