Database recovery using redundant disk arrays

The authors propose a method for using redundant disk arrays to support rapid recovery from system crashes and transaction aborts in addition to their role in providing media failure recovery. A twin-page scheme is used to store the parity information in the array, making it possible to keep the old version of the parity along with the new version. The old version of the parity is used to undo updates performed by aborted transactions or by transactions interrupted by a system failure. Using an analytical model, it is shown that the proposed method achieves a significant increase in the throughput of database systems using redundant disk arrays by reducing the number of recovery operations needed to maintain the consistency of the database