Levels of Abstraction

• Physical level: describes how a record (eg.: customer) is stored in terms of block#, sector#, byte# etc.

• Logical level: describes data stored in database, and the relationship among the data:

typedef struct customer {

string name;

string street;

integer city; }

• View level: Application programs/GUI etc hide the actual representation and present only the required data in a convenient way. Eg: Visual forms, graphical forms.

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