What is database management system? Explain Network, Hierarchical, Relational Database management system.
Database management system
In database environment the DBMS is the software that provides the interface between the data files and that program that request for user to processing the important data management functions .including
- Creating Table
- Entering and editing data
- Viewing data by using filters and forms
- Sorting the records
- Querying the database to obtain specific information
- Generating reports to print processed information
The DML (Data manipulation Language) is responsible for manipulate the data and DDL (Data Definition Language) describe how the data are stored. DBMS manage the data according to DML required and DDL description.
Hierarchical Database management system
The hierarchical model is the basis of the oldest database management system, since these data base were add as solution to immediate problems, they were created without the strong theoretical foundation that later system had their designers were familiar with file organization and data structures.
Hierarchical structure specify that an entity can have no more than a one owning entity the owning entity is called the parent the owned entity the child. A parent with no owner is called root. there is only one root in Hierarchical structure.
A parent can have many child, Where as a child can have only one parent.
Hierarchical structure specify that an entity can have no more than a one owning entity the owning entity is called the parent the owned entity the child. A parent with no owner is called root. there is only one root in Hierarchical structure.
A parent can have many child, Where as a child can have only one parent.
Networking Database management system
The network model the data structure consisting of nodes and branches. In this structure allows a node to have more than one parent The nodes of the network represent records in various types relationship between records are represented as links which become pointer in the implementation.
Relational Database management system
The relationship model was proposed by E. F. Codd in 1970. It is now widely use both mainframe and microcomputer based DBMS, because of it simplicity from the user point of view and its power.
In relational models both entities and relationship are represented by relations, which are physically represented as tables or two dimensional arrays, and attributes as column of these tables. for example if we wish to store information about students and classes, we need a table for the student and the class. A student is related to the class by being enrolled in that class. These tables are linked to each other.
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