A concave path to lowoverhead robust query processing

Karthik, S and Haritsa, JR and Kenkre, S and Pandit, V (2018) A concave path to lowoverhead robust query processing. In: 44th International Conference on Very Large Data Bases, VLDB 2018, 27 - 31 August 2018, Rio de Janeiro, pp. 2183-2195.

PDF VLDB 2018_11-13_2183-2195_2018.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

To address the classical selectivity estimation problem in database systems, a radically different query processing technique called PlanBouquet was proposed in 2014. In this approach, the estimation process is completely abandoned and replaced with a calibrated selectivity discovery mechanism. The beneficial outcome is that provable guarantees are obtained on worst-case execution performance, thereby facilitating robust query processing. An improved version of PlanBouquet, called SpillBound (SB), which significantly accelerates the selectivity discovery process, and provides platform-independent performance guarantees, was presented two years ago. Notwithstanding its benefits, a limitation of SpillBound is that its guarantees are predicated on expending enormous preprocessing efforts during query compilation, making it suitable only for canned queries that are invoked repeatedly. In this paper, we address this limitation by leveraging the fact that plan cost functions typically exhibit concave down behavior with regard to predicate selectivities. Specifically, we design FrugalSpillBound, which provably achieves extremely attractive tradeoffs between the performance guarantees and the compilation overheads. For instance, relaxing the performance guarantee by a factor of two typically results in at least two orders of magnitude reduction in the overheads. Further, when empirically evaluated on benchmark OLAP queries, the decrease in overheads is even greater, often more than three orders of magnitude. Therefore, FrugalSpillBound substantively extends robust query processing towards supporting ad-hoc queries.

Item Type:	Conference Paper
Publication:	Proceedings of the VLDB Endowment
Publisher:	VLDB Endowment
Additional Information:	The copyright for this article belongs to the VLDB Endowment.
Keywords:	Cost functions, Estimation process; Orders of magnitude; Performance guarantees; Platform independent; Query processing techniques; Selectivity estimation; Three orders of magnitude; Worst-case execution, Query processing
Department/Centre:	Division of Electrical Sciences > Computer Science & Automation
Date Deposited:	16 Aug 2022 09:00
Last Modified:	16 Aug 2022 09:00
URI:	https://eprints.iisc.ac.in/id/eprint/75926

Actions (login required)

View Item