Using non-volatile memory to improve the availability of an in-memory database

Abstract

In an in-memory database management system, non-volatile random access memories (NVRAMs) are used to store database data and control data. Because this data is stored in NVRAM, the data survives system failures. Recovery from a system failure may be accomplished more quickly by, at least in part, modifying the surviving data in NVRAM, rather than loading an entire checkpoint image and applying uncheckpointed transactions needed to synchronize the database. Because in this form of recovery the database state that serves as the starting point for applying change records is the database as stored in the NVRAM, this form of recovery is referred to herein as in-memory-based recovery. Recovery, where the database state that serves as the starting point for applying change records is a checkpoint image, is referred to herein as checkpointed-based recovery. In-memory-based recovery eliminates or reduces the need to perform certain operations that are performed for checkpointed-based recovery.