Data Base System models or Types of DBMS

1. Hierarchical Model
2. Network Model
3. Relational Model

1. Hierarchical Model or HDMS:

One of the earliest database management system was based on the Hierarchical model. Here data can be organized in the form of free structure or level-by-level manner with one limitation that is "every sub node or child node should have only one parent node".

2.Network Model or NDBMS:

To overcome the problems proposed by the hierarchical data model, the network data model was developed. It is also known as communication oriented database management system. Cross communication is possible in NDBMS.

Here data can be organized in the form of tree structure or level by level manner with cross communication. It cannot provide proper query facility,so that we have to write big programs even for small operation.It is complex in structure.

3. Relational DBMS:

RDBMS are most important database system used in the software industry today. It was Exclusively used to establish the relation the relation ship between two-database objects. One of the database objects is one table.

The Relation ship may be

One - One
One - Many
Many - One
Many - Many

Entity-Relationship Model (E-R Model):

An Entity is nothing but an object, which is physically existed in the real world.

Example: car,computer, chair

An Object in the database is a table so that an entity is nothing but a table.

Every Entity contains characters specifies its attributes simply it is a column in the table.

Data Base System models or Types of DBMS

Fundamentals of RDBMS

Data is the most important component in any work that we do. Data means collection of information or collection of raw facts.

Data base Management system is the management system or maintenance system on database.

or

It is a suit of software program for creating,maintaining & manipulating the data in database.

or

It allows the users to insert the data,to retrieve the data,to modify the data and to delete the data.

The first databases of kind existed in the form of files.
A file is nothing but collection of records.
A record is nothing but collection of information or data.

But the file system was not very efficient,it was crippled by slow data search speed. It includes the following Drawbacks.

1.Security
2.Data Redundancy
3.Data Integrity
4.Concurrency Control
5.Slow in Process

1.Security: No Login name No Password.
2.Data Redundancy: Data reputation or data duplication is very high.
3.Data Integrity: No Data Validation process.
4.Concurrency Control: No control in files system when concurrency exists.
5.Slow in Process: File System follows Sequential-searching process

Fundamentals of RDBMS