Accurate Inter-Transaction Dependency Tracking for Repairable DBMS

A reparable database management system has the ability to automatically undo the set of transactions that are corrupted by a human error or malicious attack. The key technical challenge to building repairable database management systems is how to accurately and efficiently keep track of inter-transaction dependencies that take place through a database as well as through application logic. In this paper, we present the design, implementation and evaluation of the inter-transaction dependency tracking mechanisms used in a repairable database management system called RDB2, which adds fast repairability in a portable way to a commercial DBMS Oracle 9.2.0. RDB2 eliminates dependencies due to false sharing using fine-grained inter-transaction dependency tracking, and is able to successfully identify a major source of false negatives, phantom dependencies. With these advanced inter-transaction dependency tracking mechanisms, RDB2 can significantly improve the availability of modern DBMSs by facilitating and sometimes even automating the damage repair process after an error or attack. Performance measurements on the fully operational prototypes under the TPC-C benchmark show that the run-time throughput penalty of these enhanced inter-transaction dependency tracking mechanisms is less than 18%.