Dynamic Query Re-Optimization

  • Authors:
  • Kenneth W. Ng;Zhenghao Wang;Richard R. Muntz;Silvia Nittel

  • Affiliations:
  • -;-;-;-

  • Venue:
  • SSDBM '99 Proceedings of the 11th International Conference on Scientific and Statistical Database Management
  • Year:
  • 1999

Quantified Score

Hi-index 0.00

Visualization

Abstract

Very long-running queries in database systems are not uncommon in non-traditional application domains such as image processing or data warehousing analysis. Query optimization, therefore, is important. However, estimates of the query characteristics before query exe- cution are usually inaccurate. Further, system configuration and resource availability may change during long evaluation period. As a result, queries are often evaluated with sub-optimal plan configurations. To remedy this situation, we have designed a novel approach to re-optimize suboptimal query plan configurations on- the- y with Conquest | an extensible and distributed query processing system. A dynamic optimizer considers reconfiguration cost as well as execution cost in determining the best query plan configuration. Experimental results are presented.