APEX

The recently released persistent memory (PM) offers high performance, persistence, and is cheaper than DRAM. This opens up new possibilities for indexes that operate persist data directly on the bus. Recent learned exploit distribution have shown great potential some workloads. However, none support persistence or instant recovery, existing PM-based typically evolve B+-trees without considering indexes. paper proposes APEX, a PM-optimized index concurrency, recovery. APEX based ALEX, state-of-the-art updatable index, to combine adapt best of past PM optimizations indexes, allowing it reduce accesses while still exploiting machine learning. Our evaluation Intel DCPMM shows can perform ~15x better recover from failures in ~42ms.