Database systems were invented to store huge amounts of data. The management of knowledge involves the definition of structures and therefore the provision of mechanisms for the manipulation of data. For easy maintenance of data, a proper database must be designed.
In addition, the database system must provide for the security of the data stored, within the face of system-crashes or attempts of unauthorized
access. If data is to be shared among several users, the system must avoid abnormal results.
A major purpose of a database system is to supply users with a conceptual view of data. That is, the system hides certain details of how the data
is stored and maintained.
A high-level data model lays out the database designer with a conceptual framework that specifies the data requirements of the database users and how the database is going to be structured to satisfy these requirements.
Development Lifecycle of a Database
Initial Phase: It is to completely characterize the data needs of the potential database users.
Second Phase: The designer chooses a knowledge model, and by applying concepts of the chosen data model, translates these required elements into the conceptual schema of the database.
Logical Design Phase: The designer maps the high-level conceptual schema onto the implementation data model of the database system
which will be used.
Physical Design Phase: The physical features of the database are specified. These features include the shape of file organization and therefore the internal storage structures.