1. A computer system including a first computer node and a second computer node connected to said first computer node, comprising: first storage area for storing data records; first processor for storing data record to said first storage area asynchronously with said second computer node with the free time interval; second storage area for storing the data records copied from said first storage area; and second processor for designating the record group to be read from said first storage area with the free time interval asynchronously with said first processor and then reading said record group to said second storage area for the purpose of input.