Hybrid use of non-volatile memory as storage device and cache

Abstract

Buffers in a buffer pool refer to memory locations either in local memory or in non-volatile memory used as persistent storage. The local memory and non-volatile memory have access latencies of the same order of magnitude, or a small multiple of each other. A buffer pool management system has operations to manage transitions between these states. Buffer cache copies can be avoided for read-only data, which can improve ramp-up times in database systems, increase cache capacity and improve performance of write operations. Power consumption can be reduced by avoiding memory copies and decreasing overprovisioning. These advantages can be obtained while making minimal, if any, changes to computer programs implementing the database server, particularly subsystems such as write-ahead logging and page replacement algorithms.