Two-stage transaction processing in client-server DBMSs

Shows that there is scope for replication in data-shipping client-server DBMSs, offering opportunities for improved transaction response times. To support this replication, we describe a two-stage protocol for transaction processing (2STP). We extend the conventional client-server data-shipping mechanism by allowing clients to update and query cached objects that have replicas in multiple sites. We use the concept of acceptance criteria to provide a means for the flexible handling of client updates. The effectiveness of the two-stage transaction processing mechanism is supported by means of queuing analysis and detailed simulation experiments comparing 2STP with a global lock-based data-shipping protocol. This improvement in transaction processing efficiency is achieved at the cost of longer downtimes for crash recovery