Vectorized data processing on the cell broadband engine

Abstract

In this work, we research the suitability of the Cell Broadband Engine for database processing. We start by outlining the main architectural features of Cell and use micro-benchmarks to characterize the latency and throughput of its memory infrastructure. Then, we discuss the challenges of porting RDBMS software to Cell: (i) all computations need to SIMD-ized, (ii) all performance-critical branches need to be eliminated, (iii) a very small and hard limit on program code size should be respected. While we argue that conventional database implementations, i.e. row-stores with Volcano-style tuple pipelining, are a hard fit to Cell, it turns out that the three challenges are quite easily met in databases that use column-wise processing. We managed to implement a proof-of-concept port of the vectorized query processing model of MonetDB/X100 on Cell by running the operator pipeline on the PowerPC, but having it execute the vectorized primitives (data parallel) on its SPE cores. A performance evaluation on TPC-H Q1 shows that vectorized query processing on Cell can beat conventional PowerPC and Itanium2 CPUs by a factor 20.