Types of databases

1.Relational Databases: 

Ø  In RDBMS, data is stored in tables, in form of rows and columns, where a row represent the record of the data and column represents the attributes of the record.

Ø  Relational database model has two main terminologies called instance and schema.

o   Instance is a table with rows or columns

o   Schema specifies the structure like name of the relation, type of each column and name.

Ø  For example, a student table stores the records of various students, a row of this table represents the record of a single student and the column represents the attributes of the record such as student id, name, age, address etc.

ID     Name         Age     Address 

---    ---------    ----    --------

101    Obaid         28      Mehdipatnam     

102    A. Aziz       32      Toli chowki

103    Mughaira      31      Secundrabad

104    Rahul         30      Agra

Ø  We use SQL to manage, organize and perform various operations on RDBMS.

Ø  Examples of RDBMS: MySQL, Oracle, DB2 etc.

   2.Object-Oriented Databases: 

Ø  Data is stored as objects, attributes and methods.

Ø  It typically stores and manages objects directly on the database server’s disk.

Ø  There are no tables, no rows, no columns, no foreign keys. There are only objects.

Ø  Object: It is a combination of data and its behaviour (commonly referred as methods).

o   For example: A house is an object. An object has two characteristics: States and Behaviour.

o   In this example of “House” being an object. The state of “House” is its address, color, area etc. and behaviour is Open main door, close main door etc.

 

Ø  An object-oriented database can be represented by the following diagram. 

3.Distributed Databases: 

o  A distributed database is made up of two or more files that are spread across multiple locations.

o   The database could be dispersed across many networks, housed in one physical place, or kept on several computers.

  4.Data Warehouses: 

Ø  It is a central repository for data.

Ø  A data warehouse is an information system which stores historical and commutative data from single or multiple sources.

Ø  It is designed to analyze, report, integrate transaction data from different sources whereas Database is designed to record.

Ø  It uses Online Analytical Processing (OLAP) whereas Database uses Online Transactional Processing (OLTP)

Ø  It stores data from any number of applications whereas database generally limited to single application

  5.NoSQL Databases: 

Ø  NoSQL stands for "not only SQL"

Ø  It is a type of database that is used for storing a wide range of data sets.

Ø  It is not a relational database as it stores data not only in tabular form but in several different ways.

Ø  It came into existence when the demand for building modern applications increased (unstructured and Semi-structured data).

Ø  Thus, NoSQL presented a wide variety of database technologies in response to the demands.

Ø  We can further divide a NoSQL database into the following four types:

a)     Key-value storage: It is the simplest type of database storage where it stores every single item as a key (or attribute name) holding its value, together. Examples are Memcached, Redis, Coherence 

b)    Document-oriented Database: A type of database used to store data as JSON-like document. It helps developers in storing data by using the same document-model format as used in the application code. Examples are MongoDB, CouchDB, Cloudant 

c)     Wide-column stores: It is similar to the data represented in relational databases. Here, data is stored in large columns together, instead of storing in rows. Examples are HBase, Big Table, Accumulo 

d)    Graph Databases: It is used for storing vast amounts of data in a graph-like structure. Most commonly, social networking websites use the graph database.

o   It is a graphical representation of data. It contains nodes and edges.

o   A node represents an entity, and each edge represents a relationship between two edges. Every node in a graph database represents a unique identifier.

o   Graph databases are beneficial for searching the relationship between data because they highlight the relationship between relevant data.

o   Graph databases are very useful when the database contains a complex relationship and dynamic schema.

o   It is mostly used in supply chain management, identifying the source of IP telephony.

   6.OLTP Database: 

o   OLTP stands for On-Line Transaction Processing

o   It refers to the system that manage transaction-oriented applications.

o   These systems are designed to support on-line transaction and process query quickly on the Internet. 

o   An OLTP database is a quick, analytical database made to handle lots of transactions from several users at once.

  7.Open Source databases: A database system that is open source can have either a SQL or NoSQL database as its source code.

  8.Cloud databases: 

o   A collection of organized or unorganized data that is housed on a private, public, or hybrid cloud computing platform is known as a cloud database.

o   Cloud databases are also called a database as service (DBaaS).

o   With DBaaS, a service provider handles maintenance and administrative duties.

o   Some best cloud options are:

§  AWS (Amazon Web Services)

§  Snowflake Computing

§  Oracle Database Cloud Services

§  Microsoft SQL server

§  Google cloud SQL

§  PhonixNAP