This week's book giveaway is in the Performance forum. We're giving away four copies of The Java Performance Companion and have Charlie Hunt, Monica Beckwith, Poonam Parhar, & Bengt Rutisson on-line! See this thread for details.
Batch update: you send a set of updates to the server in group in stead of one by one.
Transaction: a set of queries that logically belong together. The changes are only visible to other users when you commit the transaction. They are all reverted to the situation before the transaction started if you rollback.