Patent ID: 7383247
Filing Date: 2008-06-03
Classification: G06F,Y10S

Abstract:
1. A system for optimizing query processing in a federated information system, said system comprising: a calibrator in communication with said federated information system and adapted to intercept queries to said federated information system; a simulator in communication with said calibrator and adapted to derive alternative query plans for each of said queries, wherein each of said query plans comprises a plurality of query fragment plans associated with at least one data source, wherein said simulator is further adapted to determine first query fragment cost estimates for each of said query fragment plans, wherein said calibrator is further adapted to calibrate source-specific cost factors for each data source in said federated information system based on workload associated with said each data source by dividing an actual query fragment cost associated with processing a query fragment at a specific data source by a first query fragment cost estimate for processing said query fragment, wherein said calibrator comprises a memory adapted to store said source-specific cost factors, and wherein said simulator is further adapted to calculate second query fragment cost estimates by multiplying each of said first query fragment cost estimates times a corresponding one of said source-specific cost factors.