| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a distributed memory database system and the like in which processing for an aggregate function such as a total can be performed at high speed by reducing communication traffic volume and throughput. <P>SOLUTION: A front database server 10 has a data structure conversion section 113 and an inquiry processing section 111. The data structure conversion section 113 divides table data inputted from the outside to produce a plurality of value ID tables and stores the value ID tables while distributing them to data nodes. The inquiry processing section 111 inquires the number of appearance of a specific value ID in the table data of the data nodes on the basis of a query including an aggregate function issued from an external client machine, calculates a value of the aggregate function corresponding to the query from the number of appearance of the specific value ID returned from each of the data nodes in response to the inquiry and redirects the calculated value to the client machine. The data structure conversion section produces a plurality of value ID tables individually for each of a plurality of data items designated beforehand as a sequence that may become a tabulation axis in the table data. <P>COPYRIGHT: (C)2012,JPO&INPIT |
