Towards Transactional Data Management over the Cloud

We propose a consistency model for a data store in the Cloud and develop a framework towards the goal of deploying Database as a Service over the Cloud. This includes consistency across the data partitions and consistency of any replicas that exist across different nodes in the system. We target applications which need stronger consistency guarantees than the applications currently supported by the data stores on the Cloud. We propose a cost-effective algorithm that ensures distributed consistency of data without really compromising on availability for fully replicated data. This paper describes a design in progress, presents the consistency and recovery algorithms for relational data, highlights the guarantees provided by the system and presents future research challenges. We believe that the current notions of consistency for databases might not be applicable over the Cloud and a new formulation of the consistency concept may be needed keeping in mind the application classes that need to be supported.