By Gi-Hwan Oh, Jae-Myung Kim, Woon-Hak Kang, Sang-Won Lee | published 2012-05-20 |
1 |
Share:
Report a problem
Recently, several studies on multi-core cache-aware hash join have been carried out [Kim09VLDB, Blanas11SIGMOD]. In particular, the work of Blanas has shown that rather simple no-partitioning hash join can outperform the work of Kim. Meanwhile, the simple but best performing hash join of Blanas still experiences severe cache misses in probing phase. Because the key values of tuples in outer relation are not sorted or clustered, each outer record has different hashed key value and thus accesses the different hash bucket. Since the size of hash table of inner table is usually much larger than that of the CPU cache, it is highly probable that the reference to hash bucket of inner table by each outer record would encounter cache miss.