Integrating Query-Feedback Based Statistics into Informix Dynamic Server

: Statistics that accurately describe the distribution of data values in the columns of relational tables are essential for effective query optimization in a database management system. Manually maintaining such statistics in the face of changing data is difficult and can lead to suboptimal query performance and high administration costs. In this paper, we describe a method and prototype implementation for automatically maintaining high quality single-column statistics, as used by the optimizer in IBM Informix Dynamic Server (IDS). Our method both refines and extends the ISOMER algorithm of Srivastava et al. for maintaining a multidimensional histogram based on query feedback (QF). Like ISOMER, our new method is based on the maximum entropy (ME) principle, and therefore incorporates information about the data distribution in a principled and consistent manner. However, because IDS only needs to maintain one-dimensional histograms, we can simplify the ISOMER algorithm in several ways,...

• Type: Conference
• Year: 2007
• Where: BTW
• Authors: Alexander Behm, Volker Markl, Peter J. Haas, Keshava Murthy
• Keywords: BTW 2007, ISOMER Algorithm, One-dimensional Histograms, Reactive Qf Approach