Primary Index

[Jeremy Schubert]

I have created a database that contains the following fields:
UPC,Size/Weight,Name,Quantity,Essential,Minimum.
Below is a sample of the CSV file I'm importing.
I currently have the UPC column marked as my primary index. What would be the pros and cons of inserting an auto increment column and making that the indes?
Thx, Jeremy

0000000819534;"16 oz (454g)";"Trader Joe's Organic Crunchy Peanut Butter";;0;Y;1
0000000822701;"20 oz.";"Trader joe's Soy & Flax Clusters";;0;N;0
0000000840620;5'x150';"Concrete reinforce mesh";;0;N;0
0000000841122;10.8oz;"Trader Joes Milk Chocolate coated Pistachios";;0;Y;4
0000000845809;"32 oz (907g)";"Trader Joe's Multigrain Baking & Pancake Mix";;0;Y;2
0000000854832;"3.4 oz";"Trader Joe's Sesame Rice Crackers (Savory Thins)";;0;N;0
0000000857963;;"DCO CLASSIC PLN HORSE SHOES";;0;N;0
0000000863506;"9oz. (255g)";"Trader Joes Organic Mini Peanut Butter Sandwich Crackers";;0;N;0
0000000870429;"14.1 OZ (400 g)";"Trader Joe's White Beans with Vegetables";;0;N;0
0000000870634;"32 fl oz (1 qt) 945 mL";"Trader Joe's Organic Low Sodium Chicken Broth";;0;N;0