A Pure Lazy Technique for Scalable Transaction Processing in Replicated Databases

Recently, there have been proposals for scaling-up a database system using lazy replication. In these proposals, system scale-up is achieved through the addition of sec-ondary sites which hold replicas of the database at a pri-mary site. The addition of more secondary sites improves system performance by allowing read-only transactions to be serviced at the secondary sites. However, the scalabil-ity of the distributed system is limited by the single pri-mary site which services the update workload. As the work-load scales-up, an increasing update load is placed on the primary site, which suffers from performance degradation. We address this problem by proposing a pure lazy solution for scaling-up the database system. Our techniques provide scalability and avoid transaction inversions, which can oc-cur when transactions access stale replicas. 1