PR-join: a non-blocking join achieving higher early result rate with statistical guarantees

Online aggregation is a promising solution to achieving fast early responses for interactive ad-hoc queries that compute aggregates on a large amount of data. Essential to the success of online aggregation is a good non-blocking join algorithm that enables both (i) high early result rates with statistical guarantees and (ii) fast end-to-end query times. We analyze existing non-blocking join algorithms and find that they all provide sub-optimal early result rates, and those with fast end-to-end times achieve them only by further sacrificing their early result rates. We propose a new non-blocking join algorithm, Partitioned expanding Ripple Join (PR-Join), which achieves considerably higher early result rates than previous non-blocking joins, while also delivering fast end-to-end query times. PR-Join performs separate, ripple-like join operations on individual hash partitions, where the width of a ripple expands multiplicatively over time. This contrasts with the non-partitioned, fix...

• Type: Conference
• Year: 2010
• Where: SIGMOD
• Authors: Shimin Chen, Phillip B. Gibbons, Suman Nath
• Keywords: Database, End-to-end Query Times, Non-blocking Join Algorithm, Non-blocking Joins, SIGMOD 2010