Title :
A query sampling method for estimating local cost parameters in a multidatabase system
Author :
Zhu, Qiang ; Larson, Per-Åke
Author_Institution :
Dept. of Comput. Sci., Waterloo Univ., Ont., Canada
Abstract :
In a multidatabase system (MDBS), some query optimization information related to local database systems may not be available at the global level because of local autonomy. To perform global query optimization, a method is required to derive the necessary local information. This paper presents a new method that employs a query sampling technique to estimate the cost parameters of an autonomous local database system. We introduce a classification for grouping local queries and suggest a cost estimation formula for the queries in each class. We present a procedure to draw a sample of queries from each class and use the observed costs of sample queries to determine the cost parameters by multiple regression. Experimental results indicate that the method is quite promising for estimating the cost of local queries in an MDBS
Keywords :
database management systems; query processing; local cost parameters; multidatabase system; multiple regression; query optimization; query sampling; query sampling method; Aging; Computer science; Cost function; Database systems; Distributed databases; Optimization methods; Parameter estimation; Query processing; Sampling methods; Spatial databases;
Conference_Titel :
Data Engineering, 1994. Proceedings.10th International Conference
Conference_Location :
Houston, TX
Print_ISBN :
0-8186-5402-3
DOI :
10.1109/ICDE.1994.282996