Relational vs Non-Relational database

 

Relational vs Non-Relational database

You’ve probably come across the term database at some point in your life. Database is a set of data that is stored on a computer.

Hospitals use databases to track the treatments they administer; accountancy firms use databases to keep track of accounting records and web applications use databases to keep a list of their users and the content of their platform.

So lets start with simple question..

What is a Database?

A database is an organized collection of structured information, or data, typically stored electronically in a computer system. A database is usually controlled by a database management system (DBMS). Together, the data and the DBMS, along with the applications that are associated with them, are referred to as a database system, often shortened to just database. Within each table you can keep a record of the names entered one by one on your website. Each value in the record must match the columns in the table.

There are two main types of databases used in database management system i.e. relational and non-relational. The main difference between the two is a type of used structure.  

·       Relational databases use tables and that are all connected to each other. 

·       Non-relational databases, on the other hand, are document-oriented. Unlike tables, which are responsible for a single type of data, they can store information under different categories, which all depend on different commands.

What is a relational database?

A relational database, or relational database management system (RDMS), stores information in tables. Typically, these tables have shared information between them, causing a relationship to form between tables. This is where a relational database gets its name from.

A table uses columns to define stored information and rows for the actual data. Each table will have a column that must have unique values—known as the primary key. This column may be used in other tables, if relationships are to be defined between them. When one table’s primary key is used in another table, this column in the second table is known as the foreign key.

The most common way of interacting with relational database systems is using SQL (Structured Query Language). Developers can write SQL queries to perform CRUD (Create, Read, Update, Delete) operations.

Imagine you run an online business. You have a variety of information that you store, like customer information, order information, and products. In a relational database, this would be stored in different tables with a key to join the tables when needed.

Data is stored as tables with rows and columns in a relational database

Here, is the customer table stores the basic customer information, order id and address id. If someone needs more information on the order or address, they can query the matching order and address tables using an INNER JOIN operator with the id field. The order table in turn has product ids of the product items in the order. The details of the product are in a separate product table. This makes information organized and more structured.

What is a non-relational database?

A non-relational database, sometimes called NoSQL (Not Only SQL), is any kind of database that doesn’t use the tables, fields, and columns structured data concept from relational databases. Non-relational databases have been designed with the cloud in mind, making them great at horizontal scaling.

There are four different types of NoSQL databases.

  1. Document-oriented databases – Also known as a document store, this database is designed for storing, retrieving and managing document-oriented information. Document databases usually pair each key with a complex data structure (called a document).
  2. Key-Value Stores – This is a database that uses different keys where each key is associated with only one value in a collection. Think of it as a dictionary. This is one of the simplest database types among NoSQL databases.
  3. Wide-Column Stores – this database uses tables, rows, and columns, but unlike a relational database, the names and format of the columns can vary from row to row in the same table.
  4. Graph Stores – A graph database uses graph structures for semantic queries with nodes, edges, and properties to represent and store data.

Non-relational databases are becoming more popular as more and more businesses begin to leverage big data for analysis and reporting. Since critical data doesn’t always fit well into a pre-defined schema, NoSQL databases allow more flexibility.

When to use a relational database?

If you’re creating a project where the data is predictable, in terms of structure, size, and frequency of access, relational databases are still the best choice.

Normalization can help reduce the size of the data on disk by limiting duplicate data and anomalies, decreasing the risk of requiring vertical scaling in future.

Relational databases are also the best choice if relationships between entities are important.

Non-relational databases can store documents within the documents, which helps keep data that will be accessed together in the same place. But if this isn’t right for your needs, a relational database is still the answer. For example, if you have a large dataset with complex structure and relationships, embedding might not create clear enough relationships.

The amount of time that RDMSs have been around also means there is wide support available, from tools to integration with data from other systems.

When to use a non-relational database?

As discussed, there are many types of non-relational databases, each having their own advantages and disadvantages.

However, non-relational databases still maintain some consistent advantages. If the data you are storing needs to be flexible in terms of shape or size, or if it needs to be open to change in future, then a non-relational database is the answer.

Modern NoSQL databases have been designed for the cloud, making them naturally good for horizontal scaling where a lot of smaller servers can be spun up to handle increased load.

Why might you prefer a non-relational database over a relational database?

There are many reasons why you’d want to use a non-relational database over a relational database:

  • Non-relational databases are suitable for both operational and transactional data.
  • They are more suitable for unstructured big data.
  • Non-relational databases offer higher performance and availability.
  • Flexible schema help non-relational databases store more data of varied types that can be changed without major schema changes.

Summary

In this article, you have learned about relational vs non-relational databases and how they differ from each other. You’ve also learned the advantages and disadvantages of both types of databases and which database type is most suitable for various projects.

 

Features

Non-Relational

Relational

Availability

High

High

Horizontal Scaling

High

Low

Vertical Scaling

High

High

Data Storage

Optimized for huge data volumes

Medium to large data

Performance

High

Low to Medium

Reliability

Medium

High

Complexity

Low

Medium

Flexibility

High

Low

Suitability

Suitable For OLAP and OLTP

Suitable For OLTP

MongoDB is a non-relational database that offers scalability, high performance, reliability, and flexibility. MongoDB has grown into a wider data platform with MongoDB Atlas, MongoDB’s cloud-based database, which makes data available at all times.

 

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