NO SQL- NOT ONLY SQL

“NoSQL  just means non-relational and not SQL”

NoSQL is a class of database management system that doesn’t use structured query language for data processing. This set of database is useful while working with huge volume of data. NoSQL databases are known for being able to handle high volume data that doesn't fit the relational model, i.e. why companies like Amazon, Facebook, and Google go for it. NoSQL was an answer for all the shortcomings of relational databases. MongoDB (Document Database) is one of examples of NoSQL database.

Relational database where introduced in the late 70s to store data in an organized manner. With the arrival of social networks and more web products the amount of data has become out of control. Relational database were not designed to handle the huge amount of data

Big Data, Big Users, and Cloud Computing are taking the option of NoSQL technology as an alternative to relational databases.Examples are Apache Cassandra,CouchDB,Hadoop & Hbase,MongoDB,StupidDB,BigTable Etc.

Comparison with SQL Systems

1. More flexible, faster and high performance

2. Schema Free, No predefined Schema

3. ACID transaction properties are not needed. ACID (atomic, consistent, integrity, durable) is a set of properties that guarantees that database transactions are processed reliably.

TYPE OF NO SQL DATABASES

1.Column: Each storage block contains data from only one colum

Eg:HBase, Accumulo

2.Document: Stores documents made up of tagged elements

Eg: MongoDB, Couchbase 

3.Key-value : Allow the application to store its data in a schema-less (key, value) pairs

Eg: Dynamo, Riak, Redis, Cache, Project Voldemort 

4.Graph: Example : Neo4J, Allegro, Virtuoso