Database:
Let’s start simple. What is a database? A database is a set of data held in a computer that can be accessible in various manners. There are two main database types: Relational & Non-Relational. So, what’s the difference?
A relational database is structured, meaning the data is organized in tables. Many times, the data within these tables have relationships with one another or dependencies. A non-relational database is document-oriented, meaning, all information gets stored in more of a laundry list order. Within a single construct or document, you will have all of your data lists.
SQL(Relational):
SQL is short for Structured Query Language, which means a very firm way of sorting through data in the form of tables, columns, and rows. How is data structured in an SQL database? The table itself would be made up really of one variable or object that we would be looking through. The column would represent the data point itself that needs to be stored and the row is a record of the data points per column.
For example, if you are looking to sort data regarding what the weather is at a certain time of the day during a certain day, it would be structured as the following:
Table: Weather
Columns: Days of the Week
Rows: Time of Day
Data Points: Degrees Fahrenheit
In this structure, all queries would be related to this table and the structure of the table would allow for easy sorting, filtering, computations, etc. If we ever need to establish a connection between tables, say, you want to know what the weather was at a certain time and relate that to a baseball game’s predicted score, then what we do is create what is called a key. This key allows for connections to be made between two or more tables to solidify associations between the two.
Some popular SQL database systems include:
Oracle
Microsoft SQL Server
PostgreSQL
MySQL
MariaDB
NoSQL(Non-Relational):
In contrast to a relational database, a NoSQL database is less structured/confined in format, and thus, allows for more flexibility and adaptability. If you are going to be dealing with a dataset that isn’t clearly defined, meaning not organized or structured, you likely won’t have the luxury of establishing defined tables and relationships amongst the dataset.
For example, Facebook Messenger uses a NoSQL database, because the information that is being gathered isn’t structured enough to be segmented into tables and define relationships between each other. With tons of unstructured information, it needs to be held in a non-relational database. Think of the information as being stored on one large word document. Everything is there. As more information gets entered, the document gets longer. If you want to find and pull data, you have to in essence ‘control/command + F’ and search for the data itself.
Some popular NoSQL databases include:
Cassandra
Redis
Apache HBase
Amazon DynamoDB
Final Showdown: Pros and Cons of Relational and Non-Relational Databases:
Now we answer the question you’re really looking for. Which type of database should you use? Well, there are some questions you should ask yourself that are outlined below. If you answer yes to the relational questions, then use a SQL database. If you answer yes to the non-relational questions, then use a NoSQL database.
Pros of a Relational Database:
Data is easily structured into categories.
Your data is consistent in input, and meaning, and easy to navigate.
Relationships can be easily defined between data points.
Pros of a Non-Relational Database:
Data is not confined to a structured group.
You can perform functions that allow for greater flexibility.
Your data and analysis can be more dynamic and allow for more variant inputs.
Thank You