Concurrent Shadow Paging: Fine-Granularity Locking with Support for Extended LockModes and Early Releasing of Locks

摘要

This paper describes in detail how to implement multiple concurrent transactionswith fine-granularity locking in a database system using shadow paging for crash recovery. The basic idea is to store the updates separately until the transaction requests to commit, at which time the changes are patched to the global database. Commit batching is used to achieve reasonable performance; its gains are much higher with shadow paging than with log-based systems. Due to early releasing of locks, locking durations do not increase because of commit batching.