Russel,

Buffering is used to access data without having record locks on the data while editing it and gives you the ability to undo your data changes with tablerevert().

Transactions are used to get the "all or nothing" function. Everything between the BEGIN TRANSACTION AND END TRANSACTION does succeed or everything fails. The drawback of transaction is that the data gets lock (sometime you can't even read the data) to other users on the network while your in the middle of a transaction.

By working with transaction it's wise to make the time a transaction lasts a short as possible thereby minimizing the conccurrency problems by other users on the network.

regards,

Walter