Database Models


an integrated collection of concept for describing data , relatinship b/w data & constraints(conditions & rules regulation) n an organizations …

Components of DM :

1. structural part  :: rules & regulation which makes db

2.manipulation part ::define operation on data

3.integrity rules :: data validation

Types of DM ::

1. object Based DM : uses concepts such as entity, attr, relationships …..types r

entity relationship



object oriented

2. record based DM : db consists of a num of fixed format records of possibly

 different types

relational  :: by table , name of column should be unique .. intersection of row & column

s cell

hireracharal :: tree str , link list

network ::data s represented as a collection of records. it's a circular list, so we don;t

have to waste time in searching because nodes r connected…

3.physical DM :: index mechanism , os + dbms work, how data s stord on HD, access

mechanism of data ….