Definition

SQL is an acronym for Structured Query Language. If this will surely not help you to understand the whole thing, there is still the last word that can guide you: Language. Indeed, SQL is a language that you will use to query relational databases

SQL databases use a system that is capable of compiling an SQL query and returning the data you requested. This is called an RDBMS for Relational Database Management System. The best known RDBMS are:

ü  MySQL

ü  PostgreSQL

ü  SQLite

ü  SQL server

ü  MariaDB

ü  Oracle

In your life as a data analyst , you will mostly use MySQL or PostgreSQL because these two systems are open-source and thus free. 

Relational databases derive their name from the fact that the data are arranged in tables and that these tables are linked by a "relation" called a key. This key is nothing more than a column in each table that represents nothing more than an ID

The major advantages of using SQL databases are:

1. ü  Robustness of databases.
2. ü The data are well structured and thus easily retrievable.
3. ü  Easier to analyze data from SQL databases
4. ü  SQL is a language that is used quite extensively.
5. ü  SQL databases are comparatively inexpensive. In many cases, cloud platforms such as AWS do not load databases before introducing 2 GB of data. This is already a beautiful volume.

Here are the two main faults of SQL databases:

1. ü  Table rigidities. Usually, once the tables are defined, it is harder to change them.
2. ü  The SQL database interface is quite complicated. If you don’t know how to code in SQL, it will be difficult for you to access your data, unlike an excel sheet, for example, where you just need to open the file.

 What does NoSQL mean?

Definition:

As developers developed web applications, they needed to be more flexible. This is why we invented another way to store and query data that was later named “Not only SQL” or NoSQL.

Unlike SQL databases, this time there is no concept of relationship between tables and these look more like JSON files.

Some of the most famous NoSQL databases are:

ü  Cassandra

ü  MongoDB

ü  DynamoDB

      The major advantages of using NOSQL databases are:

ü  Flexibility

ü  Availability of data

ü  May include all types of data.

ü  Capable of handling Big Data.

ü  They integrate more easily with web applications

There are three default NOSQL values you should know:

ü  There is no relation between the tables as difficult to link the data.

ü  NoSQL databases are not easily integrated with SQL databases.

ü  Though NoSQL databases may be used in Big Data problems, they are often very expensive.

SQL vs NoSQL

Now that you have a better idea of what SQL and NoSQL are, when should you choose between them?

The major differences between them

Let us discuss the main differences between the two types of data bases:

ü  Although SQL databases are more organized, NoSQL databases are more flexible.

ü  NoSQL databases are more frequently used by web applications.

ü  SQL databases can be used to perform analyses where it is very uncommon to do so directly from NoSQL databases.

ü  Tables in NoSQL databases are never related to one another, whereas tables in SQL databases are.