Opportunities for optimism in contended main-memory multicore transactions

Main-memory multicore transactional systems have achieved excellent performance using single-version optimistic concurrency control (OCC), especially on uncontended workloads. Nevertheless, based other protocols, such as hybrid OCC/ locking and variations multiversion (MVCC), are reported to outperform the best OCC systems, with increasing contention. This paper shows that implementation choices unrelated can explain some of these differences. Our evaluation strengths weaknesses OCC, MVCC, TicToc under varying workloads contention levels, importance several called basis factors. Given sensible factor choices, does not collapse high-contention TPC-C. We also present two optimization techniques, deferred updates timestamp splitting, dramatically improve both MVCC. These techniques known, but we apply them in a new context highlight their potency: when combined, they lead gains $$4.74\times $$ for MVCC $$5.01\times TPC-C workload.