ARIES-RRH: restricted repeating of history in the ARIES transaction recovery method

摘要

A method called ARIES-RRH (algorithm for recovery and isolation exploiting semantics with restricted repeating of history) is presented which is a modified version of the ARIES transaction recovery and concurrency control method implemented to varying degrees in Starburst, QuickSilver, the OS/2 Extended Edition Database Manager, DB2 V2, Workstation Data Save Facility/VM and the Gamma database machine. The repeating history paradigm of ARIES is analyzed to propose a more efficient handling of redos, especially when the smallest granularity of locking is not less than a page, by combining the paradigm of selective redo from DB2 V1. Even with fine-granularity locking, it is not always the case that all the unapplied but logged changes needed to be redone. ARIES-RRH, which incorporates these changes, still retains all the good properties of ARIES-avoiding undo of undos, single-pass media recovery, nested top actions, etc. The fundamentals behind why DB2 V1's selective redo works, in spite of failures during restart recovery, are also explained.