Patent ID: 8433676

Claim:
A distributed transaction system, comprising: a plurality of log groups each having a unique identifier assigned thereto, a package of a data storage device storing data and a log storage device storing a log of the data; a first table provided in each of said log groups and having registered therein information about a database management device having the management right of each of the log groups; a first preparation completion log which is output to a log storage device of a global representative log group representing log groups managed by a database management device which is a coordinator in a two-phase commit of a distributed transaction in which the plurality of log groups participate, the first preparation completion log storing a list of identifiers of log groups managed by a database management device which is a participant of the distributed transaction; a second preparation completion log which is output to a log storage device of a log group managed by a database management device which is a participant in the two-phase commit, the second preparation completion log storing an identifier of the global representative log group; wherein in response to the management right of the global representative log group moving to another database management device during an in-doubt state period of the two-phase commit, the first table is rewritten to reflect moving of the management right of the global representative log group; in response to the management right of a log group other than the global representative log group moving to another database management device during the in-doubt state period of the two-phase commit, the first table is rewritten to reflect moving of the management right of a log group other than the global representative log group; a participant in an in-doubt state refers to an identifier of the global representative log group stored in the second preparation completion log and the first table and inquires about a transaction result of a database management device having a management right of the global representative log group; and the coordinator refers to a list of identifiers log groups stored in the first preparation completion log and the first table and returns a transaction result to a participant in response to receiving an inquiry about the transaction result from the participant in the in-doubt state.