Survey on Optimization B+ Tree Index for Persistent Memory

The advent of persistent memory(PM) introduces new perspectives for index structure design while presenting challenges in data consistency,persistence overhead,and concurrency control.As a widely adopted index structure in storage systems,the B+ tree requires tailored adaptations to harness PM’s unique features,including byte-addressability,non-volatility,and low latency.This paper focuses on the optimization of B+ tree indexes for persistent memory,beginning with an analysis of the challenges in designing PM-based B+ trees.Then,optimization strategies are reviewed from two perspectives:PM-only architectures and DRAM-PM hybrid architectures.For PM-only architectures,advancements in data consistency mechanisms,concurrency control optimizations,and innovative leaf node designs are summarized,with an emphasis on enhancing write operation efficiency while ensuring instant recovery.For DRAM-PM hybrid architectures,strategies based on leaf node structure optimization and auxiliary structure enhancement are examined,highlighting approaches to improve indexing performance through selective persis-tence.Finally,a detailed analysis of the design characteristics,advantages,and limitations of optimization schemes under both architectures is presented,offering insights into future research directions for B+ tree index optimization in these contexts.