Database management systems are designed to
manage databases. A database management system
(DEMS) is a software system that uses a standard
method to store and organize data A database management system receives instruction from a database administrator (DBA) and accordingly instructs the system to make the necessary changes. These commands can be to load, retrieve or modify existing data from the system
1) Hierarchical Database
A hierarchical database is a design that uses a one-to-many relationship for data elements. Hierarchical database models use a tree structure that links a number of disparate elements to one “owner,” or “parent,” primary record
The network database model allows each record to have multiple parent and multiple child records, which, when visualized, form a web-like structure of networked records. In a hierarchical model, data members can only have a single parent record but can have many child records.
3) Relational Databases
RDBs organize data in different ways. Each table is known as a relation, which contains one or more data category columns. Each table record (or row) contains a unique data instance defined for a corresponding column category.
4) Object-Oriented Database
The object-oriented database model is an alternative implementation to that of a relational model. An object-oriented database is similar in principle to an object-oriented programming language. An object-oriented database management system is a hybrid application that uses a combination of object-oriented and relational database principles to process data.
5) Graph Databases
A graph database also referred to as a semantic database, is a software application designed to store, query, and modify network graphs. A network graph is a visual construct that consists of nodes and edges.
6) ER Model Databases
An Entity-Relationship (ER) Diagram is a type of flowchart that illustrates how “entities” such as people, objects, or concepts relate to each other within a system.