1. THE BwTree: A RANGE INDEX FOR MODERN HARDWARE

Database platform support for efficient ranking can have positive performance implications for a number of rank-aware applications, including data exploration, social net-work analysis, and keyword search. This talk highlights two pieces of work where ranking appears in the research area of database architectures for new hardware. First, we highlight the Bw-tree, a new high-performance B+-tree supporting sorted key-sequential access. The Bw-tree is re-architected to run efficiently on new hardware: its in-memory opera-tions are completely latch-free, removing blocking behavior while also improving multi-core cache behavior, while its storage layer implements a novel log-structured flash storage layer for that exploits fast sequential writes and mitigates adverse performance impact of random writes. Second, we highlight a new classification technique for identifying cold (infrequently accessed) data in main-memory database sys-tems. Using a log of sampled record accesses, our tech-nique estimates record access frequencies using exponential smoothing. This classification approach is very efficient: it is able to accurately identify hot and cold records among 1M records in sub-second time from a log of 1B record accesses on a workstation class machine