Introduction
For carrying out the working of the management information systems in a very efficient and a proper way, the data acts as a very essential and a critical part for the transaction processing. In the beginning, when the era of the computer applications literally started, the data used to be maintained on the basis of the use of a particular data for some particular application.

In such a scenario, every user system used to have its own master files and also the transaction files, but a very important point to be kept in mind here is that these transaction files and the master files were processed separately.

One of the major observations included the presence of the data redundancy. This data redundancy is generally caused because of the fact which says that the data which is mainly needed by the systems is common and as a result of this, repetition creeps in the data stored in the various user systems. And this data redundancy further leads to the complexities in the data management.

Data redundancy also leads to the lack of the integrity and the in consistency of the data available in the various user files.

The name ‘The Database Management System’ comes from the database approach that emerged out of the need, indeed urgency, to eliminate the data management problems. Database is actually very pivotal to The Database Management System. The database also uses a very specific structuring of the data but the actual meaning of the word database can be defined as “A mechanical or an automated, formally defined, centrally controlled collection of the data in an organization”.

The Database Management System An Overview
The Database Management System is software that provides services for the accessing of a database, while maintaining all the required features of the data.

The Database Management System DBMS has the responsibility for acting as the interface between the various application programmes and the data. The Database Management System acts as a software system and also helps in performing the functions like the defining, creating, revising, and the controlling of the database.

The Database Management System in a very basic sense is a specially designed software, used in order to create the database and also for maintaining the database. It helps in performing the individual business applications to extract the data, which is required by them without the creation of the separate files in their computer programs.

The collection of the information that is stored in the database at a specific moment is referred to as the instance of the database. The over all design of the database is referred to as the database schema.

Characteristics of the data in the Database Management System
1. Sharing of the data takes place amongst the different type of the users and the applications.
2. Data exists permanently.
3. Data must be very much correct in the nature and should also be in accordance with the real world entity that they represent.
4. Data can live beyond the scope of the process that has created it.
5. Data is not at all repeated.
6. Changes that are made in the schema at one level should not at all affect the other levels.

Advantages of the Database Management System
1. Helps in reducing the complex nature of the systems environment due to the central control or the management of the data, access, utilization and the security.
2. Reduces the data redundancy and also the inconsistency as the same data elements are not at all repeated.
3. Also promotes the integrity of the data throughout the system or an organization.
4. Provides for the central control of the data creation and also for the definition.
5. Reduces or completely finishes the confusion that creeps in to the data.
6. Reduces the costs relating the program development and the maintenance.
7. Separates the logical view and the physical arrangement.
8. Reduces the program data dependence.
9. Permits the ad hoc queries.
10. Provides flexibility in the information systems.
11. Increases access and availability of the information.

Components of Database Management System are

1. Transaction Management
a. Acts as the sequence of the database operations, which further represent the logical unit of the work.
b. A transaction has the ability to update, delete or also modify a single or a set of the records.
c. When the Database Management System does a ‘commit’ the changes made by the transaction are made permanent.
d. If the changes are not to be made permanent, the transaction can be rolled back and then the database will remain in its original form.

2. Con Currency Control
a. Acts as the database management activity of coordinating the actions of the database manipulation process.
b. The goal of a good and an efficient con currency control is to allow the con currency while maintaining the consistency of the share data.

3. Recovery Management
a. Provides full assurance about the aborted or the failed transactions that these do not create an adverse affect on the database.
b. Ensures that the database is returned to the consistent state after a transaction fails.
c. Recovery relates to the con currency, more is the con currency the more is the chance that an aborted transaction can affect many other transactions.

4. Security Management
a. Involves the protection of the data.
b. Only authorized users are able to access the data in the database.

5. Language Interface
a. Provides support languages.
b. These are used for the definition and also for the manipulation of the data in the database.

6. Storage Management
a. The Database Management System involves a method for the management of the permanent storage of the data.
b. The internal schema tells and explains how the data should be stored by the storage management mechanism.
c. And the storage manager interfaces with the operating system in order to access the physical storage.

7. Data Catalog Management
a. Also called as the Data Dictionary.
b. Acts as the system database containing description of the data in the database.
c. Has information about the data, the relationships, the constraints and the schema.

Different types of the database languages can be summarized as the following

1. Data Definition Language (DDL)
a. Acts as the formal language.
b. Generally used by the various computer professionals.
c. Helps in the specification of the database schema.
d. The result of the compilation of the Data Definition Language statements is a set of the tables.
e. Defines each of the data element at it appears in the database.

2. Data Manipulation Language (DML)
a. Acts as a very specialized language.
b. Mainly used by the end users and the programmers.
c. Helps in manipulating the data in the database.
d. Provides the facility for the retrieval of the information that has been stored.
e. Helps in the insertion of the new information.
f. Also helps in deleting some particular information.
g. Modifies the stored information.
h. Consists of some commands.
i. These commands help in the extraction of the data from the database.
j. Satisfies the information requests.
k. Helps in the development of the applications.

Types of the Data Manipulation Language
1. Procedural Data Manipulation Language
a. Requires the user in order to specify what data are needed and how to get those data.

2. Non Procedural Data Manipulation Language
a. Needs the user for specifying the data that are needed without specifying how to get those data.

Data Dictionary acts as an automated or a manual, active or a passive file which has the ability to store the definitions of the data elements and the data characteristics. The Data Dictionary is actually the repository of the information about the data. Data Dictionary defines each of the data elements and also gives it a name for the easy access.

Data Dictionary acts as the core or the hub of the database management system, is the third component of the database management system. The Data Dictionary provides with the following information –
1. The name of the data item.
2. The description of the data item.
3. The sources of the data.
4. The impact analysis.
5. Keywords that are used for the categorization and the search of the data item descriptions.

Functions of the Data Dictionary
1. Defines the data element.
2. Helps in the scheduling.
3. Helps in the control.
4. Permits the various users who know which data is available and how can it be obtained.
5. Helps in the identification of the organizational data irregularity.
6. Acts as a very essential data management tool.
7. Provides with a good standardization mechanism.
8. Acts as the corporate glossary of the ever growing information resource.
9. Provides the report facility, the control facility along with the excerpt facility.