Dremel: Interactive Analysis of Web-Scale Datasets
Dremel is a scalable, interactive ad-hoc query system for
analysis of read-only nested data. By combining
multi-level execution trees and columnar data layout, it
is capable of running aggregation queries over
trillion-row tables in seconds. The system scales to
thousands of CPUs and petabytes of data, and has thousands
of users at Google. In this paper, we describe the
architecture and implementation of Dremel, and explain how
it complements MapReduce-based computing. We present a
novel columnar storage representation for nested records
and discuss experiments on few-thousand node instances of
the system.
Google