Introduction to database management systems

DATA BASE MANAGEMENT SYSTEM

INTRODUCTION TO DATABASE MANAGEMENT SYSTEMS (DBMS):

Why Database

 Characteristics of Data in Database

 DBMS,

 What is database Advantage of DBMS

INTRODUCTION: -

     1.  The technology for creating and managing databases is refers to Data base management system (DBMS).

     2.  Collection of inter-related data which helps in efficient retrieval, deletion and insertion of data from database and organization of data in the form of tables, schemas, views, reports etc.

    3.  Data Base Management System is a software tool to organize i.e. create, retrieve, update, and manage data in a database.

     4.  Some software i.e. used to store data in the form of database are DBASE IV OR V, Microsoft ACCESS, or EXCEL.

Why database: -

     1.  By using DBMS we can develop software applications in less time.

     2.  In DBMS, there is independence of data and efficient use of data.

     3.  We can use uniform data administration.

    4.  DBMS provide data integrity and security.

    5.  Data can be accessed concurrently and it can be easily recovered from crashes.

    6.  Use of DBMS is user-friendly and declarative query language.

Characteristics of data in Database: -

        Characteristics of Database are as follows:  -

Real world entity: -

                A modern DBMS is more realistic and it uses real world entities which design its architecture. DBMS uses the behaviour and attributes.

Relation based tables: -

               As a user we can easily understand the architecture of a database just only looking at the table names because of it allows entities and relations to form tables.

Isolation of data and application: -

               The data of a database system is entirely different. An active entity of a database, whereas data is said to be passive on which the database works and organizes. It also stores metadata which means data about data, to ease its own process.

Less redundancy: -

               Due to normalization data is splits in a relation when any of its attributes is having redundancy in values and DBMS follows the rules of normalization. The scientific process that reduces data redundancy in a mathematical way is known as normalization. 

Consistency: -

               State where every relation in a database remains consistent in termed as consistency. As compared to earlier forms of data storing application like file-processing systems a DBMS can provide greater consistency. 

Query language: -

               Query language makes more efficient to retrieve and manipulate data, DBMS is equipped with query language. User can use or apply different filtering options required to retrieve a set of data.  

Backup and recovery: -

               There is chances of failure of whole database at a time at that time no one will able to get that data  back and which may cause huge loss. The only solution is that to take a backup of the database and use is whenever in need. 

ACID Properties: -

               Atomicity, Consistency, Isolation, and Durability normally shortened as ACID, and this concepts is followed by the DBMS. The concepts of ACID are applied on transactions which are used to manipulate data in a database.

Multiple views: -

               For different users DBMS offers multiple views. In any company a department of production will have a different view of databases than a person working in the sales department having different view. 

Multiuser and concurrent Access: -

               To access and manipulate data in parallel way DBMS supports multi user environment. 

Security: -

               Users are unable to access data to other users and departments. While entering data into the database and retrieving the same data at a later stage DBMS offers methods to impose constraints. DBMS also offers many different level of security features.

DBMS: -

     1.  A collection of related data known as database, data is a collection of facts and figures which can be processed to produce meaningful information.

     2.  In other terms data is mostly representation of recordable facts. We add data to produce information that are based on facts.

    3.  For example, suppose we are making data about marks obtained by all students of a class, from that we can conclude about students result about their marks obtained and also conclude who is topper or average marks.

     4.  DBMS stores data in such a way that it becomes easier to find the information retrieve of data, manipulation of data and production of information.

     5.  Users of DBMS: -

DBMS users have different rights and permissions that use it for different purposes. Some users use it to retrieve data and some users use to back it up (backup). The users are broadly categorized as follows: - 

   

     a.  End users: - Those who actually raise the benefits of having DBMS are end users. They work as viewers who pay attention on the market rates to sophisticated users such as business analyst.

    b.  Administrators: - Administrators are the maintainer of the DBMS and they are responsible for administrating the data. Access profiles for users and apply limitations and security are looked by administrators.

    c.   Designers: - Designer is not a single person work it is the group of people who work on the designing part of the database. Their work is to identify and design set of entities, relations, constraints, and views.

Advantages of DBMS: -  

        1.  Data independence: -

                                                               i.    Application program should be free or independent possible from details of data representation and storage.

                                                                  ii.       It can supply an abstract view of the data for insulating code of application from facts.

    2.  Efficient data access: -

                                                                  i.    Data Base Management System utilizes a mixture of discreet concepts and techniques for storing and retrieving of data.

                                                             ii.    In case where the data is stored on external storage devices efficient data access becomes important.

    3.  Data integrity: -

             The DBMS can enforce integrity constraints on the data, if data is accessed through the DBMS.

     4.  Data administration: -

                                                             i.        Sharing of data by the several users, integrating the administration of data can   offer some significant improvements.

                                                      ii.    The nature of data are understand by experienced professionals, and being managed and can be responsible for the organization of data representation to reduce the redundancy and make the retrieval of data efficient.