Abstract: A computing system includes a database and a processing device. The database includes a data part which stores data and an index part which stores an incomplete index of the data. The processing device receives a query from a client, processes a query by using the incomplete index, and transmits a response to the query to the client.

Abstract: A data storage unit that stores saving target data including a plurality of attribute values, and data identification information including any one of the attribute values included in the saving target data, as a data pair; and a data structure conversion unit that changes the attribute value included in the data identification information of the data pair stored in the data storage unit, to another one of the attribute values included in the saving target data stored as the data pair, are included. During a period of time that the data structure conversion unit is changing the attribute value included in the data identification information, reference to the data pair, which is the target of the change by the data structure conversion unit, is prohibited.