| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a distributed query processor for efficiently measuring and collecting the number of output records for calculating an SF value for appropriately performing query division in a data sharing type multi-database system.SOLUTION: A distributed query processor includes: multi-database management data 10 for managing database information; a distributed query generation part 11 for analyzing a user query, and for selecting an appropriate query processing engine under the output data size and engine information of each processing of the user query to generate a distributed query; a measurement query generation part 12 for generating a measurement query for measuring the number of output records of the user query; a measurement part 13 for executing the measurement query; a query execution control part 14 for executing the processing of the user query; and a data updating part 15 for calculating the number of records or an SF value from the execution result of the user query or the measurement query to update the database information.</p> |
