Abstract: A database management system for executing database operations in parallel by a plurality of nodes and a query processing method for it are described. The database management system contains a decision management node for deciding a distribution node for retrieving information so as to analyze a query received from an application program, generate a processing procedure for processing the query, and execute the process and a join node for sorting, merging, and joining the information retrieved by the distribution node. When the query process is executed, the distribution node decided by the decision management node retrieves the information to be processed and the join node decided by the decision management node also obtains the result for the query from the retrieved information. The query result is outputted from an output node and transferred to the application program.

Abstract: A parallel database system retrieval method and system for transferring from database operation servers to a front end server only those data items that are used in subsequent processing, thereby shortening the query time when the unused data are massive. The invention allows an initial retrieval query to transfer only location information about the target data from a database operation server to the front end server. Using the location information the invention permits a subsequent query to get variable-bound location information so that the latter query will retrieve a desired sub-data item according to the acquired location information and dictionary information about the sub-data item locations within the data.