Character String Aggregation in Numerical Aggregation

A method includes preparing a character string management table for managing character strings, a character string field, and a numerical field corresponding to the character string field in hierarchy structure data of a MOLAP, generating, in response to character string data being input into the character string field, a unique character string ID for a character string of the character string data and storing the character string ID into the numerical field, storing the character string ID and the character string data into the character string management table, calculating an aggregated value of the numerical fields by the numerical aggregation calculation of the MOLAP at a higher hierarchy layer of the hierarchy structure data, resolving the aggregated value into separate character string IDs at the higher hierarchy layer, and referring to the character string management table to obtain and display character string data corresponding to the resolved character string IDs.