01.Explain the behavior of the internal components of the DBMS architecture?

Data base management system (DBMS) is a software system that allows users to define, create maintain a database and provides controlled access to the data. DBMS is basically a collection of programs that enables users o store, modify and extract information from a database as per the requirements. DBMS is an intermediate layer between programs and the data.

A database management system (DBMS) consists of several components. Each component plays very important role in the database management system environment. The major components of database management system are:

·         Software

·         Hardware

·         Data

·         Procedures

·         Users

1.      HARDWARE: The hardware is the actual computer system used for keeping and accessing the database. It consists of a set of physical electronic devices such as computers (together with associated I/O devices like disk drives), storage devices, I/O channels, electromechanical devices that make interface between computers and the real world systems etc, and so on. It is impossible to implement the DBMS without the hardware devices, In a network, a powerful computer with high data processing speed and a storage device with large storage capacity is required as database server. 

2.       SOFTWARE: The main component of a DBMS is the software. It is the set of programs used to handle the database and to control and manage the overall computerized database. DBMS software itself, is the most important software component in the overall system.

3.      DATA: Data is the most important component of the DBMS. The main purpose of DBMS is to process the data. In DBMS, databases are defined, constructed and then data is stored, updated and retrieved to and from the databases. The database contains both the actual  data and the metadata.

4.      PROCEDURES: Procedures refer to the instructions and rules that help to design the database and to use the DBMS. The users that operate and manage the DBMS require documented procedures on hot use or run the database management system. 

5.      USERS: The users are the people who manage the databases and perform different operations on the databases in the database system. There are three kinds of people who play different roles in database system

         i.            Application Programmers

        ii.            Database Administrators

      iii.            End-Users

DATA BASE ARCHITECTURE.

  The data base architecture divided in three parts:

INTERNAL LEVEL

CONCEPTUAL LEVEL

EXTERNAL LEVEL

INTERNAL LEVEL:

·         Physical representation of the Data Base on the computer.

·         How the data is stored in the database.

·         Physical implementation of the Data Base to achieve optimal run–time performance and storage space utilization.

- Storage space allocation for data and indexes
- Record description for storage
- Record placement
- Data compression

CONCEPTUAL LEVEL:

conceptual or conceptual scheme –perform a full description of structure of the database but did not offer details  the data stored in the data base .Conceptual schema describe the record and relationship included in the conceptual view

EXTERNAL LEVEL:

The external level interacts directly with the user (end users or application programs). It changes the data coming from the conceptual level to a format and view that is familiar to the users.