Multi-level recovery

Abstract

Multi-level transactions have received considerable attention as a framework for high-performance concurrency control methods. An inherent property of multi-level transactions is the need for compensating actions, since state-based recovery methods do no longer work correctly for transaction undo. The resulting requirement of operation logging adds to the complexity of crash recovery. In addition, multi-level recovery algorithms have to take into account that high-level actions are not necessarily atomic, e.g., if multiple pages are updated in a single action.In this paper, we present a recovery algorithm for multi-level transactions. Unlike typical commercial database systems, we have striven for simplicity rather than employing special tricks. It is important to note, though, that simplicity is not achieved at the expense of performance. We show how a high-performance multi-level recovery algorithm can be systematically developed based on few fundamental principles. The presented algorithm has been implemented in the DASDBS database kernel system.

Data recovery for web applications

“…Compensating transactions have been used to recover from the effects of long-running or committed transactions [34,36] and for recovery in multi-level systems that are designed to increase concurrency [49,38]. We also use compensating transactions to perform recovery, but our focus is on recovering from application bugs or vulnerabilities that cause data corruption, and we target web applications that may not use transactions.…”

Trusted Recovery from Information Attacks

“…In long duration transaction models( [GMS87], [WR91]), or in multilevel transaction models ( [WHBM90], [Lom92]), it is possible to extract the read information of transaction (subtransaction) T from its compensation log records, where the action of T"s compensating transaction is recorded.…”

An open and safe nested transaction model: concurrency and recovery

“…To exploit layer speci®c semantics at each level of operation nesting, Weikum presented a multilevel transaction model (Weikum, 1991;Weikum et al, 1990). The model provides non-strict execution by taking into account the commutative properties of the semantics of operations at each level of data abstraction, which achieves a higher degree of concurrency.…”