In oracle, the index on an index ordered table only needs be a unique. So, for example: 1234 "John Doe" null null null 5824 "John Doe" "Sale 1" "it

In oracle, the index on an index ordered table only needs be a unique. So, for example: 1234 "John Doe" null null null 5824 "John Doe" "Sale 1" "item 1" $5 4321 "John Doe" "Sale 1" "item 2" $50 4382 "John Doe" "Sale 2" "item 1" $4 CREATE UNIQUE INDEX (name, sale, item);