1. A database server apparatus comprising: a data storage unit configured to store data; a committing procedure information storage unit configured to store committing procedure information for committing each of a plurality of transactions that updates data stored in the data storage unit; a data creating unit configured to create yet-to-be-committed update data from the stored data by executing a transaction for updating the data upon receipt of the transaction; a determining unit configured to determine whether there is a committed transaction that creates committed data as source update data before the transaction executed by the data creating unit is committed; and a committing unit configured to commit the transaction for re-updating the yet-to-be-committed update data in accordance with the committed data and the committing procedure information, when the determining unit determines that there is the committed transaction.