Please use this identifier to cite or link to this item:
|Title:||Optimizing complex queries with multiple relation instances||Authors:||Cao, Y.
|Issue Date:||2008||Citation:||Cao, Y.,Das, G.C.,Chan, C.-Y.,Tan, K.-L. (2008). Optimizing complex queries with multiple relation instances. Proceedings of the ACM SIGMOD International Conference on Management of Data : 525-538. ScholarBank@NUS Repository. https://doi.org/10.1145/1376616.1376671||Abstract:||Today's query processing engines do not take advantage of the multiple occurrences of a relation in a query to improve performance. Instead, each instance is treated as a distinct relation and has its own independent table access method. In this paper, we present MAPLE, a Multi-instance-Aware PLan Evaluation engine that enables multiple instances of a relation to share one plrysical scan (called SharedScan) with limited buffer space. During execution, as SharedScan pulls a tuple for any instance, that tuple is also pushed to the buffers of other instances with matching predicates. To avoid buffer overflow, a novel interleaved execution strategy is proposed: whenever an instance's buffer becomes full, the execution is temporarily switched to a drainer (an ancestor blocking operator of the instance) to consume all the tuples in the buffer. Thus, the execution is interleaved between normal processing and drainers. We also propose a cost-based approach to generate a plan to maximize the shared scan benefit as well as to avoid interleaved execution deadlocks. MAPLE is light-weight and can be easily integrated into existing RDBMS executors. We have implemented MAPLE in PostgreSQL, and our experimental study on the TPC-DS benchmark shows significant reduction in execution time. © Copyright 2008 ACM.||Source Title:||Proceedings of the ACM SIGMOD International Conference on Management of Data||URI:||http://scholarbank.nus.edu.sg/handle/10635/40409||ISBN:||9781605581026||ISSN:||07308078||DOI:||10.1145/1376616.1376671|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Nov 20, 2019
checked on Oct 28, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.