High performance temporal indexing on modern hardware

摘要

Transaction time databases can be put to a number of valuable uses, auditing, regulatory compliance, readable backups, and enabling multi-version concurrency control. While additional storage for retaining multiple versions is unavoidable, compression and the declining cost of disk storage largely removes that impediment to supporting multi-version data. Not clear has been whether effective indexing of historical versions, can be achieved at high performance. The current paper shows how temporal indexing can exploit the latch-free infrastructure provided for the Bw-tree by the LLAMA cache/storage subsystem to support high performance. Further, it demonstrates how the LLAMA mapping table can be exploited to simultaneously enable migration of historical data, e.g. to cloud storage, while overcoming the index node time splitting difficulty that has arisen in the past when historical nodes are migrated.