1. A data distributed search system comprising: a management computer including a processor and a memory; a plurality of search execution computers each including a processor and a memory; and a network connecting the management computer and the plurality of search execution computers, wherein the memory of the management computer stores instructions that cause the processor of the management computer to execute: a distributed administration manager for receiving a plurality of graphs, each of the graphs holding at least one relation connecting a data value with another data value and being composed of data pieces connected by the at least one relation, and distributing the graphs to the plurality of search execution computers; and a distributed search manager for sending search conditions to the plurality of search execution computers upon receipt of the search conditions and receiving search results from the plurality of search execution computers, wherein the distributed administration manager of the management computer classifies two or more of the graphs including at least one common relation as a group and distributes and allocates the graphs belonging to the group among the plurality of search execution computers, wherein the distributed search manager of the management computer sends search conditions, including a first search condition on a data relation and a second search condition on a data value, to each of the plurality of search execution computers to request to conduct a parallel search, wherein, for each of the search execution computers, the memory thereof stores instructions that cause the processor thereof to execute: a graph storage module for storing the graphs received from the management computer; and a search execution module for searching the graphs stored in the graph storage module with the search conditions received from the management computer and returning a search result to the management computer, wherein the search execution module in each of the plurality of search execution computers extracts graphs matching the first search condition as possible solutions and conducts condition matching on data values included in the graphs extracted as possible solutions with the second search condition to acquire a data piece of which the data value matches the search condition on data value as the search result.