The Database Model

The types of the database models usually used in the business organizations is classified as follows –

1. Hierarchical data Base Model (HDBM)

a. Is one among the earliest information base management systems.

b. This model has information logically united to several relationship.

c. Follows a structured structure mode.

d. needs a controlled, finite and a rule based mostly approach.

e. Represents information during a pointed or a tree like structure.

f. every record seems to be like associate structure chart with one high level phase, referred to as the basis, spreading down into the branches and also the leaves.

g. there's a record.

h. at intervals every record, the information components square measure organized into the items of record that square measure noted because the segments.

i. associate higher phase is connected to a lower phase during a parent kid relationship.

j. A parent phase might have quite one kid.

k. a toddler will have just one parent.

l. the foremost common ranked information base management system has been the data Management System (IMS) discharged by the IBM within the year 1968.

2. Network data Base Model (NDBM)

a. Acts because the variation of the higher than ranked information Base Model.

b. This model has information logically as several–to– many relationship.

c. Helps in understanding and conjointly helps in analyzing the sales Zone performance.

d. Analysis the sales and also the recovery position.

e. Analysis the merchandise wise sales performance.

3. Relational database Model (RDBM)

a. most up-to-date of the 3 information models.

b. Was projected by Dr. E.F Cod within the year 1970.

c. Consists of the information within the information as straightforward 2 dimensional tables referred to as because the relations.

d. The table consists of the rows and conjointly the columns.

e. Rows represent the individual records.

f. The columns represent the attributes of every of the record.

g. the data in additional than one file is simply extracted.

h. This data is any combined to suit the user’s specific necessities.

i. The 3 basic operations of this model square measure choose, Project, Join.