Database access characterization for buffer hit prediction

Abstract

Presents a database access characterization method that first distinguishes three types of access pattern from a trace-locality within a transaction, random accesses by transactions, and sequential accesses by long queries. The authors describe a concise way to characterize the access skew across the randomly accessed pages by assuming that the large number of data pages may be logically grouped into a small number of partitions, such that the frequency of accessing each page within a partition can be treated as equal. They present an extensive validation of the buffer hit predictions, both for single-node as well as multiple-node systems, based on access characterization using production database traces. This approach can be applied to predict the buffer hit probability of a composite workload from those of its component files.<>