A Database Management System (DBMS) is a program that allows the computer users to create and access a database and it employs the use of the database with computer as a platform so that the data can be manipulated and can be retrieved by requesting the DBMS software of an organization and its end users.
It enables large organizations to entrust the task of organization-wide database development into the hands of database administrators (DBAs) and other specialists.
It can be defined as system software which integrates all the present set of data records and files of an organization.
It enables different database users to run different application programs without even worrying about how the data would be shared between the application programs and the DBMS, so in result accessing of database is much easy. DBMSs can use any of the available database models, such as the network model or relational model for its data.
Flat Files
In database management, a flat file is defined as an individual file which is capable of holding all the information of an organization in a single table.
For a comparison, we see that the relational database has two or more tables having a defined relationship to each other while in flat files only single table usage is employed.
A flat file is only related to itself and not to any other tables present in data.
File Management System
The file management system (FMS) is such a system in which all data and information is stored on a single large file.
The main disadvantage of this system is that when we are searching for a record or data, it consumes a lot of time. This drawback led the FMS creators to the introduction of the concept of indexing in this system.
Moreover, the FMS system had other drawbacks too; to quote few examples like updating or modifications to the data cannot be handled easily, sorting the records was time consuming and so on.
These entire shortcomings led to the introduction of the Hierarchical Database System.
Hierarchical Database System
Hierarchical Database System made amend for the time consuming part of accessing and sorting records present in previous system FMS by the introduction of parent-child relationship between records in database.
Root of the data is defined as the origin of the data from where several other branches have their data at different levels and the last level is called the leaf.
The major drawback of this system was that if there is any need for modification of data or we want some addition made to the structure then our whole structure would have to be changed in order to accommodate for that change, so making this task a tedious one.
In order to avoid this problem, the next database system took its origin which is called as the Network Database System.
Network Database System
Network Database System employed the concept of many-many relationships between data entities.
This also followed the previous technology of pointers to define relationships.
It is a database organization method that allows for data relationships in a net-like form. A data entity can point towards multiple data entities and can itself be pointed to by other data entities.
Relational Database System
A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd.
A RDBMS may be defined as DBMS software in which data is stored in tables form and the relationship among the data is also stored in tables form.
Nearly all commercial and open source databases available are based on the relational model.
The idea behind the introduction of Relational Database System was that whenever the data has to be entered, it get organized as tables and each record forms a row with many fields or attributes in it. This was carried out to make amends for the shortcomings prevalent in the previous database systems.
Relationships between different tables are created by the use of RDBMS also.
Although at the present time, relational database systems remain the most dominant choice for both transactional and analytical applications, newer structures are competing with RDBMSs in data warehouse applications; for example in column-oriented and correlation database systems.
Object-oriented database
An object-oriented database is a database model in which information is portrayed in objects form like as done in object-oriented programming.
The merging of the database capabilities along with object-oriented (OO) programming language capabilities results in an object database management system (ODBMS).
The need of ODBMS arises from the fact that the information available in today�s world comprises of not only data but video, audio, graphs, and photos which are defined as complex data types. As a contrast, Relational DBMS aren�t capable of supporting these complex data types.
As the database in merged with the programming language feature, the programmer can easily check the data integrity and consistency within one environment as both the OODBMS and the programming language are using the same model of representation.
If we want to support complex data types in Relational DBMS projects, the projects would then have to be divided into two separate tasks: which are the database model and the application.
Object-relational database (ORD)
An object-relational database (ORD), or object-relational database management system (ORDBMS), is a database management system (DBMS) which has great resemblance with a relational database, but it further includes an object-oriented database model: objects, classes and inheritance are directly supported in database schemas and in the query language
Moreover, we can extend the data model according to our required custom data-types and methods.
ORD can be thought of lying in between the relational databases and object-oriented databases (OODBMS).
In object-relational databases, the data storing and controlling method is technically same as that employed in relational database which is that the data resides in the database and is manipulated collectively with queries in a query language.
Data warehouse
Data warehouse is a repository of an organization's electronically stored data.
Data warehouse is employed to support managers in decision making tasks. Data warehouses contain data which portrays the present business conditions of an organization at a point of time.
The idea behind the introduction of data warehousing is due to an organisation�s need for correct, amalgamated, unique and merged reporting and analysis of its data, at separate levels of aggregation.
Web enabled
The landscape of Web-based instruction is changing rapidly as the mergence of the Web and database servers is ongoing.
Web-enabled database servers enhance Web-based instructions and it facilitates and provides benefits to both students and instructors.
Web-based database server has many advantages. To quote some examples, they facilitate virtual communities for discussion, present linked resources in relational databases, provide instant feedback, and customized instructional sequences.
