NoSQL encompasses a huge variety of database technologies which have been developed through a rise in the mass of data
Firstly let’s start by looking what NoSQL is. NoSQL encompasses a huge variety of database technologies which have been developed through a rise in the mass of data which is stored about users and through their products and objects. The frequency that this data is accessed and the processing needs are also differing. Relational databases though were not designed to cope with this scale of data or accessibility and challenges needed to be overcome.
SQL is a hugely outdated system which no longer meets a lot of business requirements which is where NoSQL comes in. NoSQL is the solution for a vast amount of enterprises, but a lot of people are unsure as to whether NoSQL is the only solution to move forward with. There are a vast amount of differences between the technologies which will be touched upon below.
In regards to data storage SQL models store data in a relational model through rows and columns where rows contain all of the information about one particular entry. The columns, therefore, are all the separate data points which you may have about a particular row. For example, if you had a row about a specific brand of car the columns may include model, make, color etc. With NoSQL models, a host of databases is used, each of which has different data storage models. This can include document, key-value, columnar and graph.
With SQL databases each record conforms to a schema which is fixed, this means that the columns need to be decided upon and locked before data entry can be made. This can be amended at a later date but it can involve altering the entire database. As opposed to NoSQL where the schemas are dynamic and information can be added at any point, a row doesn’t even need to contain data for each column.
Within SQL scalability is vertical which means that when you have a larger amount of large it can result in you needing a larger server which can get pretty expensive. It is possible to scale an RDBMS across all of the servers but this can prove tricky and take a long time. In contrast, NoSQL has a horizontal structure which means that data is spread across databases. This is done because multiple servers are used which can result it in being much cheaper and a much more cost- effective option than SQL servers.

What are the different NoSQL database types?

Document databases

They pair each key with a document which is a complex data structure and these documents may contain different key-value pairs (sometimes multiple ones).

Graph stores

These are used to record information about other networks including social connections. These can include Neo4J and HyperGraphDB.

Key-value stores

These are certainly the simplest NoSQL database as every item within a database is stored as a key name alongside its value.

Wide-column stores

These include Cassandra and HBase which are optimized for queries across large data sets and can store columns of data together as opposed to rows.

As you can see there are a vast amount of differences between SQL and NoSQL, and while on the surface it may seem that there is no question that NoSQL is better, each businesses needs are different so be sure to look into yours before making a decision.