> I'd like to remember that Hive supports ACID (in a very early stages yet) but > most often that is a feature that most people don't use for real production > systems.
Yes, you need ACID to maintain multiple writers correctly. ACID does have a global primary key (which is not a single integer) - ROW__ID. select ROW__ID, * from acid_table; will return a unique value for each row. Cheers, Gopal
