Course Title: Database Management System (CS403)

Lecture No. 4:

Internal or Physical View / Schema

Inter Schema Mapping

Data Independence

Functions of DBMS

DBMS Environments

Conclusion

Internal or Physical View / Schema

This is the level of the database which is responsible for the storage of data on the storage media and places the data in such a format that it is only readable by the DBMS. Although the internal view and the physical view are so close that they are generally referred to a single layer of the DBMS but there lays thin line which actually separated the internal view from the physical view. As we know that data when stored onto a magnetic media is stored in binary format, because this is the only data format which can be represented electronically, No matter what is the actual format of data, either text, images, audio or video. This binary storage mechanism is always implemented by the Operating System of the Computer. DBMS to some extent decides the way data is to be stored on the disk. This decision of the DBMS is based on the requirements specified by the DBA when implementing the database. Moreover the DBMS itself adds information to the data which is to be stored.

NEXT