PrestaShop/PrestaShop — pull request #2059 by iNem0o (2014-08-21 15:14:24+00:00)
Title: [*] CORE : Additional index added to ps_orders on "references" to improve performance

Trying to find an order by reference will produce a full table scan because there is no index on the column.

This will improve performance during order creation, or during a search by reference in BO