Many of today’s applications need massive real-time data processing. In-memory database systems have become a good alternative for these requirements. These systems maintain the primary copy of the database in the main memory to achieve high throughput rates and low latency. However, a database in RAM is more vulnerable to failures than in traditional disk-oriented databases because of the memory volatility. DBMSs implement recovery activities (logging, checkpoint, and restart) for recovery proposes. Although the recovery component looks similar in disk- and memory-oriented systems, these systems differ dramatically in the way they implement their architectural components, such as data storage, indexing, concurrency control, query processing, durability, and recovery. This survey aims to provide a thorough review of in-memory database recovery techniques. To achieve this goal, we reviewed the main concepts of database recovery and architectural choices to implement an in-memory database system. Only then, we present the techniques to recover in-memory databases and discuss the recovery strategies of a representative sample of modern in-memory databases.

中文翻译：

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主存数据库恢复

当今的许多应用程序都需要海量实时数据处理。内存数据库系统已成为满足这些要求的一个很好的替代方案。这些系统在主内存中维护数据库的主副本，以实现高吞吐率和低延迟。但是，由于内存易失性，RAM 中的数据库比传统的面向磁盘的数据库更容易出现故障。DBMS 为恢复建议实施恢复活动（日志记录、检查点和重新启动）。尽管恢复组件在面向磁盘和内存的系统中看起来很相似，但这些系统在实现其架构组件的方式上存在巨大差异，例如数据存储、索引、并发控制、查询处理、持久性和恢复。本调查旨在对内存数据库恢复技术进行全面审查。为了实现这个目标，我们回顾了数据库恢复和架构选择的主要概念，以实现内存数据库系统。只有这样，我们才会介绍恢复内存数据库的技术，并讨论现代内存数据库的代表性样本的恢复策略。