FineLine: log-structured transactional storage and recovery

Recovery is an intricate aspect of transaction processing architectures. In its traditional implementation, recovery requires the management of two persistent data stores---a write-ahead log and a materialized database---which must be carefully orchestrated to maintain transactional consistency. Furthermore, the design and implementation of recovery algorithms have deep ramifications into almost every component of the internal system architecture, from concurrency control to buffer management and access path implementation. Such complexity not only incurs high costs for development, testing, and training, but also unavoidably affects system performance, introducing overheads and limiting scalability. This paper proposes a novel approach for transactional storage and recovery called FineLine. It simplifies the implementation of transactional database systems by eliminating the log-database duality and maintaining all persistent data in a single, log-structured data structure. This approach not only provides more efficient recovery with less overhead, but also decouples the management of persistent data from in-memory access paths. As such, it blurs the lines that separate in-memory from disk-based database systems, providing the efficiency of the former with the reliability of the latter.