Introduction to NoSql

In the later post, we’ve seen why there is a requirement of NoSql databases. In this post we will see what are NoSql databases and how we use them.
NoSql databases, well obviously, unlike relational databases, have no schema. In other word, NoSql databases are schemaless (however, actually, it’s not the whole story).

While data is saved in the form of tables in relational databases, NoSql databases uses simple documents or simple .txt files for the most part to save data. The format use to save data is fancy JSON.

Above figure shows NoSql format on the left and relational format on the right. This is a simple, yet powerful comparison between Relational and NoSql dbs. The text files are scalable, thus making NoSql scalable, while, as we’ve discussed previously, this is not true for Relational databases.

There are four different techniques to make NoSQL viable in the real world. They are:

1. Key-Value Store – It has a Big Hash Table of keys & values {Example- Riak, Amazon S3 (Dynamo)}
2. Document-based Store- It stores documents made up of tagged elements. {Example- CouchDB}
3. Column-based Store- Each storage block contains data from only one column, {Example- HBase, Cassandra}
4. Graph-based-A network database that uses edges and nodes to represent and store data. {Example- Neo4J}

I hope you’d have enjoyed our journey so far with NoSql databases.

Happy Reading.