Poker: permutation-based SIMD execution of intensive tree search by path encoding

We propose POKER, a permutation-based vectorization approach for vectorizing multiple queries over B+-trees. Our key insight is to combine vector loads and path-encoding-based permutations to alleviate memory latency while keeping the number of key comparisons needed for a query to a minimum. Implemented as a C++ template library, POKER represents a general-purpose solution for vectorizing the queries over indexing trees on multi-core processors equipped with SIMD units. For a set of five representative benchmarks evaluated with 24 configurations each, POKER outperforms the state-of-the-art by 2.11x with one single thread and 2.28x with eight threads on an Intel Broadwell processor that supports 256-bit AVX2, on average.