Neil Aggarwal wrote: > There are a few things we do: > 1. When we place an order, we commit the order to the database in > a transaction. > 2. In a separate transaction, we reduce the qty available of the > product by the amounts ordered. This transaction may be > a conflict with other transactions. That is OK. > 3. The inventory management system keeps the master inventory > of the products. We have a continuous job that pulls the > latest updates to the inventory and feeds those updates > back to the web database. > > So, even if an inventory number is wrong for a short time, it will > be updated to an accurate number soon. > that may be OK for an order processing system, but it could be a serious problem for something like a banking system where you are dispersing cash.