Computer system and transaction processing management method

A computer system has a database constructed from storage areas in each of a plurality of computers, which stores data including an operation number for managing an operation status by transaction processing. The data is allocated to the computers in accordance with predetermined management ranges, and the computers include a control module configured to generate an operation history indicating specifics of each operation included in the piece of transaction processing in a case of receiving an execution request. A distribution module determines a sequence number of applying a plurality of operation histories to the database and transmits them to the other computers. A conflict judgment module determines whether a piece of transaction processing corresponding to an operation history conflicts based on the operation number; and an applying module operates the database based on an operation history corresponding to a piece of transaction processing to the database determined not to conflict.