Daniel Abadi in Data Management In the Cloud concludes that cloud computing is more suitable for large scale data analysis as oppose to transactional based system. Thus more research is expected in this area.
Part of the reason why are as follows:-
1. Transactional application does not necessarily adopt a share nothing model.
2. Maintaining ACID properties for transaction over cloud is complex.
More research in cloud computing's database evolve around the following areas:
a) fault tolerance - continue query execution in the advent of failure
b) heterogeneous cluster
c) easy of use