Types of Databases

Types of Databases

As described by Linux Information Project, Data is a collection of distinct pieces of information, particularly information that has been formatted (i.e., organized) in some specific way for use in analysis or making decisions.
Thus, database is defined as a set of data that has a regular structure and that is organized in such a way that a computer can easily find the desired information.
Databases offer an organized mechanism for storing, managing and retrieving information.

Types of Databases
1. Centralized Database

Centralized Database

-       Information/Database is located at a centralized location

-       Users from different location can access and process data using application procedures

-       For verification and validation of end users, different authentication procedures are applied, which is handled by local area office

-       Example: “Nepal Telecom (NTC) has a centralized database for registration of applications for new telephone connections. The data regarding the applicant are received from a local area office of NTC.

Data validation and verification is carried out by the application programs at the central computer center, and a registration number is allotted by the application programs located at the central facility. The local area office keeps on recording it and hardly does any processing”

2. Distributed Database

Distributed Database

-       As opposite to Centralized Database, here data is not located at one place and is distributed at various sites of an organization.

-       Distributed Database has contributions from the common database as well as the information captured by local computer.

-       All databases are connected to each other with the help of communication links which helps them to access the distributed data easily.

-       For Example: “imagine a distributed database as a one in which various portions of a database are stored in multiple different locations(physical) along with the application procedures which are replicated and distributed among various points in a network.”

-       There are Two kinds of Distributed Databases (DDB). They are

-       a. Homogeneous DDB: The databases which have same underlying hardware and run over same operating systems and application procedures are known as homogeneous DDB, for e.g. All physical locations in a DDB.

-       b. Heterogeneous DDB:  Whereas, the operating systems, underlying hardware as well as application procedures can be different at various sites of a DDB which is known as heterogeneous DDB.

3. Personal Database

-       Data Collected and Stored on a Personal Computers

-       Small and Easily manageable

-       Data is generally used by the same department of an organization

-       Accessed by small group of people

-       These DBs are generally subject specific and user designed

-       They use simple and less powerful DBMS packages available on PCs and may not have all the features of Relational Database Management System (RDBMS) but have similar limited features.

4. End-user Database

-       Here, End User is not concerned about the transaction or operations done at various levels and is only aware of the product which may be a software or an application.

-       This is a shared database which is specifically designed for the end user like managers at different levels.

-       These managers may not be concerned about the individual transactions as in operational databases. Rather, they would be more interested in summary information.

-       Although, the operational databases can also generate summary information from the transaction details, they would be quite slow as they are not designed for this purpose.

5. Commercial Database

-       These are the paid versions of huge databases designed uniquely for the users who want to access information for help.

-       These databases are subject specific, and one cannot afford to maintain such a huge information

-       Such database is provided through commercial links

-       These databases may offer statistics regarding commodity, foreign exchange and stock markets, companies and their performance, importers and their buying patterns, decided case laws, etc.

6. NoSQL Database

-       NoSQL is an acronym for “Not Only SQL”

-       It is an alternative to traditional RDBMS and are especially useful for working with large sets of distributed data.

-       NoSQL databases can be schema agnostic, allowing unstructured and semi-structured data to be stored and manipulated (Rouse, 2011).

Different types of NoSQL databases are as follows

a.     Document databases: These databases pair each key with a complex data structures known as a document. Documents can contain many different key-value pairs, or key-array pairs, or even nested documents.

b.     Graph Stores: These databases are used to store information about networks of data, such as social connections. Graph Stores include Neo4J and Giraph.

c.     Key-Value Stores: These are the simplest NoSQL databases. Every single item in the database is stored as an attribute name (or ‘key’), together with its value. Example of key-value stores are Riak and Berkeley DB. Some key-value stores, such as Redis allow each value to have a type, such as ‘integer’, which adds functionality.

d.     Wide-Column Stores: Databases such as Cassandra and HBase are optimized for queries over large datasets, and store columns of data together, instead of rows (MongoDB, 2019).

7. Operational Database

-       Data related to the operations of enterprise are stored

-       This database Manages and Stores data in real time.

-       Generally, such databases are organized on functional lines such as marketing, production, employees, etc.

-       Operational database is the source for a data warehouse.

-       Elements in an Operational database can be added and removed on the fly.

-       These databases can be either SQL or NoSQL based, where the latter is geared toward real-time operation.

-       These data are collected from sensors, machines, IOT, Media, Transactions, etc.

8. Relational Database

-       These databases use table-like schemas and store the data in disk

-       They are good to store business data

-     Here, database is categorized by a set of tables and the tables consists of rows and columns where the columns has an entry for data for a specific category and rows contains instance for that defined according to the category.

-       The Structured Query Language (SQL) is the standard user and application program interface for a relational database.

-       Some of the major RDBMS are SQL Server, Oracle, MySQL, PostgreSQL, etc.

9. Cloud Database

-       Database that is accessible to client from the cloud and delivered to users on demand via the internet from a provider’s server (Webopedia.com, 2019).

-       A type of database service that is built, deployed and delivered through a cloud platform.

-       Also referred to as Database-as-a-Service (DBaaS), cloud databases can use cloud computing to achieve optimized scaling, high availability, multi-tenancy and effective resource allocation.

-       A cloud database typically works as a standard database solution that is generally implemented through the installation of database software on top of a computing/infrastructure cloud (Techopedia.com, 2019).

-       It may be directly accessed through web browser or a vendor provided API for application and service integration.

10.  Object-oriented Database

-       Object-oriented Database (OODB) represents data in the form of objects and classes

-       These databases follow the fundamental principles of Object-Oriented Programming (OOP)

-       Object – Oriented Programming + Relational Database = Object – Oriented Database Model (Sivabalan, 2019)

-       An object-oriented database is organized around objects rather than actions, and data rather than logic. For example: a multimedia record in relational database can be a definable data object, as opposed to an alphanumeric value.

11.  Graph Database

Graph Database Property Graph

-       Also called a graph-oriented database, is a type of NoSQL database that uses graph theory to store, map and query relationships.

-       It is essentially a collection of nodes and edges. Each node represents an entity (such as a person or business) and each edge represents a connection or relationship between two nodes. Every node in a graph is defined by a unique identifier, a set of outgoing edges and/or incoming edges and a set of properties expressed as key/value pairs.

-       Graph Database are well-suited for analyzing interconnections, which is why there has been a lot of interest in using graph databases to mine data from social media.

-       They are also useful for working with data in business disciplines that involve complex relationships and dynamic schema, such as supply chain management, identifying the source of an IP telephony issue and creating “customers who bought this also looked at…” recommendations (Rouse, 2019).

References

Algorri, M. (2016). [online] Available at: https://www.quora.com/What-are-the-different-types-of-databases [Accessed 18 Mar. 2019].

MongoDB. (2019). NoSQL Databases Explained. [online] Available at: https://www.mongodb.com/nosql-explained [Accessed 18 Mar. 2019].

Rouse, M. (2011). What is NoSQL (Not Only SQL database)? - Definition from WhatIs.com. [online] SearchDataManagement. Available at: https://searchdatamanagement.techtarget.com/definition/NoSQL-Not-Only-SQL [Accessed 18 Mar. 2019].

Rouse, M. (2019). What is graph database? - Definition from WhatIs.com. [online] WhatIs.com. Available at: https://whatis.techtarget.com/definition/graph-database [Accessed 18 Mar. 2019].

S, S. (2018). Database: Six Important Types of Databases | Business Management. [online] Your Article Library. Available at: http://www.yourarticlelibrary.com/database/database-six-important-types-of-databases-business-management/10375 [Accessed 18 Mar. 2019].

Sam, S. (2018). Types of databases. [online] Tutorialspoint.com. Available at: https://www.tutorialspoint.com/Types-of-databases [Accessed 18 Mar. 2019].

Sivabalan, V. (2019). What is an Object-Oriented Database? | Study.com. [online] Study.com. Available at: https://study.com/academy/lesson/what-is-an-object-oriented-database.html [Accessed 18 Mar. 2019].

Techopedia.com. (2019). What is a Cloud Database? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/26523/cloud-database [Accessed 18 Mar. 2019].

Webopedia.com. (2019). What is a cloud database? Webopedia Definition. [online] Available at: https://www.webopedia.com/TERM/C/cloud_database.html [Accessed 18 Mar. 2019].