1. A data management method of managing shared data which is shared by a plurality of processes and data inherent in a process which exists during execution of one particular process and disappears when the process is finished, comprising the steps of: checking, when each process fetches shared data from a data base into a memory, whether the shared data requires data inherent in the process; determining the inherent data of the process if necessity for the data is determined; storing the determined inherent data of the process in the memory; and storing a pointer for the inherent data of the process, which is stored in the memory, into the fetched shared data in accordance with attributes inherent in the process requiring the inherent data of the process.