A column in the column set to be used as the primary key or as unique.
You cannot specify the QITS column to be either UNIQUE or a PRIMARY KEY. See “QITS_column_name” description.
If more than one column_name is specified, the PRIMARY KEY or UNIQUE column set is based on the combined values of the column named.
A maximum of 64 columns can be specified for a primary key.
Columns listed in a UNIQUE or PRIMARY KEY table constraint must all be defined as NOT NULL.