Title
Cache-conscious buffering for database operators with state
Abstract
Database processes must be cache-efficient to effectively utilize modern hardware. In this paper, we analyze the importance of temporal locality and the resultant cache behavior in scheduling database operators for in-memory, block oriented query processing. We demonstrate how the overall performance of a workload of multiple database operators is strongly dependent on how they are interleaved with each other. Longer time slices combined with temporal locality within an operator amortize the effects of the initial compulsory cache misses needed to load the operator's state, such as a hash table, into the cache. Though running an operator to completion over all of its input results in the greatest amortization of cache misses, this is typically infeasible because of the large intermediate storage requirement to materialize all input tuples to an operator. We show experimentally that good cache performance can be obtained with smaller buffers whose size is determined at runtime. We demonstrate a low-overhead method of runtime cache miss sampling using hardware performance counters. Our evaluation considers two common database operators with state: aggregation and hash join. Sampling reveals operator temporal locality and cache miss behavior, and we use those characteristics to choose an appropriate input buffer/block size. The calculated buffer size balances cache miss amortization with buffer memory requirements.
Year
DOI
Venue
2009
10.1145/1565694.1565704
DaMoN
Keywords
Field
DocType
resultant cache behavior,good cache performance,appropriate input buffer,database operator,common database operator,operator temporal locality,temporal locality,runtime cache,initial compulsory cache,multiple database operator,hash table,database management systems,storage virtualization
Cache-oblivious algorithm,Cache invalidation,Cache pollution,Cache,Computer science,Parallel computing,Real-time computing,Page cache,Cache algorithms,Cache coloring,Smart Cache,Database
Conference
Citations 
PageRank 
References 
14
0.80
19
Authors
3
Name
Order
Citations
PageRank
John Cieslewicz133519.95
William Mee2151.17
Kenneth A. Ross34110750.80