There exists many types of database management system to store entities such as Centralized database,No-sql Database,Relational Databases.There are multiple types of database management systems such as relational, object, and document which are mostly used. In this article we discuss the types of Database Management Systems or DBMS.
Types of Database Management Systems
- Hierarchical databases
- Network databases
- Relational databases
- Object-oriented databases
- Graph databases
- ER model databases
- Document databases
It is the type of database that stores data at a centralized database system. It is beneficial as it has decreased the risk of data management, i.e., manipulation of data will not affect the core data. Also one of the major parts being data consistency is maintained as it manages data in a central repository.It often faces a major problem as it is very large therefore the time required to fetch the data increases It is not easy to update such an extensive database system and If any server failure occurs, entire data will be lost, which could be a huge loss.
It is very fast and simple. In a hierarchical database, records contain information about there groups of parent/child relationships, just like as a tree structure. The structure implies that a record can have also a repeating information. In this structure Data follows a series of records, It is a set of field values attached to it. It collects all records together as a record type. These record types are the equivalent of tables in the relational model, and with the individual records being the equivalent of rows. To create links between these record types, the hierarchical model uses these type Relationships.
This database is based on the relational data model, which stores data in the form of rows(tuple) and columns(attributes), and together forms a table(relation). A relational database uses SQL for storing, manipulating, as well as maintaining the data. Each table in the database carries a key that makes the data unique from others.
Properties of Relational Database
A transaction is a small unit of a program that must maintain Atomicity, Consistency, Isolation, and Durability − commonly known as ACID properties − in order to ensure accuracy, completeness, and data integrity.
Atomic : All operations in a transaction succeed or every operation is rolled back which means that either a task is fully completed and if not it is rolled back.
Consistent : On the completion of a transaction, the database is structurally same.
Isolated: Transactions do not contend with one another. Contentious access to data is moderated by the database so that transactions appear to run sequentially.
Durable : The results of applying a transaction are permanent, even in the presence of failures.
ACID properties mean that once a transaction is complete, its data is consistent and stable on disk, which may involve multiple distinct memory locations.
NO SQL DATABASES
It is not a relational database as it stores data not only in tabular form but in several different ways. It came into existence when the demand for building modern applications increased. In the NoSQL database world, ACID transactions are less fashionable as some databases have loosened the requirements for immediate consistency, data freshness, and accuracy in order to gain other benefits, like scale and resilience. It follows BASIC properties:
Basic Availability : The database appears to work most of the time.
Soft-state: Stores don’t have to be write-consistent, nor do different replicas have to be mutually consistent all the time.
Eventual consistency: Stores exhibit consistency at some later point. BASE properties are much looser than ACID guarantees.
A Database is a logical, consistent and organized collection of data that it can easily be accessed, managed and updated.
DBMS is a collection of programs that facilitates users to create and maintain a database.
The collection of database and DBMS software together is known as a database system.