Physical design requires the definition of specific storage or access methods that will be used by the database. Within the DBMS?s confine, the physical design must include as estimate to the space required to store the database. The required space estimate is translated into the space to be reserved within the available storage devices.
Physical storage characteristics are a function of the DBMS and the operating systems being used. Most of the information necessary to perform this task is found in the technical manuals of the software you are using. For example, if you use IBM?s OS/2 Database Manager Version 1.2, an estimate of the physical storage required for database creation (empty database) would be provided by a table such as the shown in Table 2.4.