Druid: A Real-time Analytical Data Store

Abstract

Druid is an open source data store designed for real-time exploratory analytics on large data sets. The system combines a column-oriented storage layout, a distributed, shared-nothing architecture, and an advanced indexing structure to allow for the arbitrary exploration of billion-row tables with sub-second latencies. In this paper, we describe Druid's architecture, and detail how it supports fast aggregations, flexible filters, and low latency data ingestion.