PURPOSE: To effectively utilize a data base resourse by setting and utilizing reference information for managing a block area within a data base system.

CONSTITUTION: The system is provided with a computation reference setting part 3 registering information to be the computation reference of the area using situation of the data block in the system and a conversion table 4 to mutually convert the unused area ratio of the data block and area management information. The system is also provided with a conversion table generating part 5 generating the conversion table 4 based on computation reference information and a block search part 6 searching area management information to search the data block to be a record processing object. Besides. the system is provided with a record update part 7 which record-processes and an area management information update part 8 updating area management information of the data block. A user can specify information to be the computation reference of area management information under a data base circumstance peculiar to the user.