Database Management System

Introduction to Database Management System 

Every organization have to maintain data concerning their activities, business, transaction, employees etc. For example, your school maintains data regarding a student's general information, academic performance, punctuality and discipline. These data need to be kept in such a way that it can be readily available and can be presented easily in desired formats. The data also needs to be updated and appended regularly. Actually, these data are manually maintained in various files in most cases. As you can notice in the below Table - Telephone directory, it has information distributed under the headings, such as S.No. Name, Address, Telephone Number. Furthermore, the entire information is alphabetically organized for easy retrieval.

Well organized information as above is database. In other words, a collection of systematically organized inter-related data is called a database.

Data and Information

Raw form of any facts, figures or entities are known as data. Data alone does not give any meaning. For example, Aaradhya, 1000, account, balance etc. are raw data individually does not give any meaning. 

The processed form of data is known as information. When the data becomes information it gives meaningful result. For example, Aaradhya has 1000 balance in his bank account. Here Aaradhya, 1000, account, balance all have their significant meaning. Thus, we can say that information is the organized collection of inter-related data.

Purpose of Database 

Database is used to store, organize and retrieve data. Database can be computerized and non-computerize (manual). A database may have single table or multiple tables. The data in a database are organized in rows and columns. Some examples of database are Telephone directory, mark ledger, attendance register, dictionary etc.

Database Management System (DBMS) 

Database management system (DBMS) is a computerized system that stores data, processes them and provides information in an organized form. DBMS basically deals with the creation of database, its management and retrieval process. Creating, modifying, updating, appending, organizing, sorting, removing, and retrieving are the major tasks performed easily, efficiently and accurately using Database management system. Some of the popular DBMS software are MS-Access, Oracle, MS-SQL Server, MySQL, PostgreSQL etc. 

These DBMS are capable to handle records in multiple tables on the basis of a key field. It allows a user to view or retrieve records from the multiple linked tables continuously at a time.

Features of DBMS The following are the features of a DBMS:  Large volume of data can be stored and updated easily. 

 Provides data integrity and security. 

 Easy in data administration or data management. 

 Provides the data sharing facility. 

 Reduces the data redundancy (duplication of data). 

 Provides concurrent access, recovers the data from the crashes. 

 Supports centralized control 

Components of Database 

Table 

Database is composed of one or more tables. Tables are the building block of database. A single table is used to store data of a specific purpose or subject such as telephone directory, book records in library etc. Since entire data is managed and kept in a table for the future retrieval process it is also called the primary object of database. Table stores large volume of data into rows called records and column called field. When fields and records are combined forms a complete table.

Record 

A record or row contains information about single items in a database. It is also called tuple. For example, in Table – Book Records, all the information about a book is record. Here, the combination of Code, Book Name, Level, Author, Year of Publication values forms a record. 

Field

A field or column contains information about a certain type for all records. It is also known as attributes. For example, in Table – Book Records, Code, Book Name, Level, Author, Year of Publication are the fields of book records table. 

Query is an object of MS Access that is used to view , retrieve , change and analyze  record from table. Query is very powerful tool. 

Form is graphical interface used for entering data in table. With the help of form we can add data change data, delete data and view data from database.

Report is also object in MS Acess that is used to create and maintain data as final data.