In a database system having a dictionary/directory for collective management of definition information of the database system, when an application program is compiled to generate an object module, it is confirmed, by referring to the definition information stored in the dictionary, if a database access instruction in the application program is correctly operable. The confirmed definition information is incorporated within an object module which is edited to generate a load module. During execution of the load module, a database access control is effected using the definition information of the database system in the directory as well as the definition information incorporated at the compiling stage.