MongoDB vs PostgreSQL: A Comparison

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MongoDB vs PostgreSQL: A Comparison

If you’re new to database management, there are many options for you to start your own system and here we will see how MongoDB and Postgres differ from one another, make no mistake, Postgres and MongoDB are both amazing database management systems that can help you establish control and manage your databases easily, but both of them have their own personality that can help you decide on which to use for your project.

MongoDB as we all know is the leading document database that’s built on a well-distributed, scale-out architecture and has an intricate comprehensive platform that is cloud-based to help manage and deliver data to applications. It can handle transactional, operational, and analytical workloads at different scales. MongoDB would be your choice if your project will heavily utilize DevOps and agile methods, developer productivity, and building projects that can scale with ease. 

While on the other hand, PostgreSQL offers a rock-solid enterprise-grade SQL database that is open source and has a huge community, and is future-proof due to its massive potential for growth. PostgreSQL can help you manage databases with its mass array of options and tools. It can be the best choice if you’re planning on serving up hundreds and thousands of queries from hundreds of tables, and if you’re familiar and can dabble with SQL, and push SQL to its absolute limit, PostgreSQL is the right tool for you.

Now we will now do an intricate comparison between MongoDB and PostgreSQL as to which of them can help you the most. Let’s start with their backgrounds and how they work.

PostgreSQL (Object-Relational Database)

First of all, PostgreSQL is a very powerful open-source object-relational database management system with emphasis on its extensibility and standards compliance that utilizes and expands the SQL language while combining many features that can securely store and scale up even the most complicated data workloads and being open-source gives it vast potential for future growth for potential databases. It is also ACID-compliant, transactional, and stores important data using table formats while giving the user flexibility with its use of constraints, triggers, roles, stored procedures, and views as the core components. 

A traditional RDBMS

PostgreSQL is an RDMBS (relational database management system), that uses script schemas and it requires primary keys, and you cannot add data to it unless the data column for it is already existing

MongoDB (Cross-platform Document-Oriented Database)

While PostgreSQL is an RDMBS, MongoDB is a NoSQL database where every record is a document that's comprised of key-value pairs that reminisce of a JSON object with schemas. It is also flexible, allowing its users to create databases, schema, tables, and more.  A basic unit of MongoDB is made of documents identifiable with a primary key. MongoDB users can utilize the Mongo shell that provides a JavaScript interface in which the users interact and carry out CRUD operations through it. Simply we can say that MongoDB is more of a general-purpose document-based database that is designed for modern application developers and is licensed under the Server Side Public License

A JSON database

Unlike PostgreSQL and other RDMBS, a JSON database like MongoDB has no schema so you can put basically anything into it. In contrast that with a SQL database where you must define its structure before you put data that looks like this:

data: {
attribute:  value

‍What Exactly Do You Need a Database For?

As displayed above, both MongoDB and PostgreSQL have many features and unique quirks that can help you manage databases and they are made to be dependable. to further narrow down your choice it simply boils down to what type of database you’re going to use and its demands, whether it will be a document database or a relational database.


MongoDB will be a huge help if you’re planning on a database designed for analytics and transactions-based applications that are working with constantly changing data.

SQL databases will surely benefit from PostgreSQL with its multiple tools that will help with your databases and its huge potential due to its huge community and its open-source model.


But most of the time, the real question isn’t MongoDB vs PostgreSQL, but rather the best document database vs the best relational database.

And it is quite often, at the beginning of a development project, project leaders end up having to bet on a choice and hope that it’s the best fit.

Now here are some of the major aspects that your can compare both Postgres and MongoDB to further narrow down which of them can help you on your project:


PostgreSQL's structure allows it to be very secure and reliable due to the tight governing rules of database structure, giving PostgreSQL a huge advantage over MongoDB when it comes to security. Due to its high reliability and security, PostgreSQL is the ideal structure for your database system for banking systems.

Also, PostgreSQL offers many authentication methods which include a pluggable authentication module or a PAM, and lightweight directory access protocol or LDAP which highly reduce the attack surface of the servers. with these, it ensures server-level protection through host-based authentication and certificate authentication. PostgreSQL can use SSL certificates because it provides data encryption when your data transits through the web public network highways. CCA tools or client certificate authentication tools are also available as an option thus allowing the use of cryptogenic functions to store encrypted data.

‍Support & Community

PostgreSQL boasts its large, open community and with it being open-sourced, it has a huge ecosystem that can help you with any queries you have. PostgreSQL also is frequently updated and developers, third-party companies, and even enthusiasts provide huge support and give feedback to further expand its reach and stability which helps the development of the system  and even making small modifications to its database system which furthers its potential and making it more future-proof

Like PostgreSQL, MongoDB has a community that helps users connect and interact with each other to answer their inquiries and questions. They also share extensive knowledge and give out tutorials for beginners to follow.

ACID Compliance

ACID transactions are one of the most important features of a relational database and it makes writing applications simpler. 

Considered as one of the most important features of relational databases is ACID transactions which allow the user to make writing applications simpler. PostgreSQL utilizes the read committed isolation level by default as long as isolation levels within the database transactions are concerned. Also allows the users ability to tune the read committed isolation level up to its serializable isolation levels.

A relational database utilizes the data to be modeled across independent parent-child tables in a tabular schema, allowing transactions various changes to the database to either be made or rolled back in a group while on the other hand, document databases have it easy because they collate data in a document while executing transactions and it doesn't need a multi-document transaction due to the nature of reading and writing is an atomic operation.


PostgreSQL supports extensibility in several different ways, including stored functions and procedures. Extensibility is simply the attribute of being intended to allow the addition of new capabilities or operations. Relational databases frequently store information on tables, databases, columns, etc. in system catalogs, which is what makes PostgreSQL so broad. Although the user sees these "data dictionaries" as tables, the database system actually stores data in them.

Additionally, PostgreSQL may dynamically load user-written code into itself. PostgreSQL keeps the information about the tables, columns, and data types that are present in addition to information about the functions, access methods, and data types. Users frequently need specific functionality that can be provided through shared libraries. PostgreSQL is uniquely suited for rapid prototyping of new applications because users can simply specify the code file, and PostgreSQL will load it as necessary. In contrast, MongoDB has eventually evolved into extensible, allowing users to create their own functions and use them within the framework. Similar to user-defined functions (UDF), it enables users of relational databases (like PostgreSQL) to modify SQL statements.


To sum up, so far, we’ve covered the basic details of PostgreSQL and MongoDB alike. We’ve discussed their history, key features, and what makes them different. While both PostgreSQL and MongoDB make amazing databases, it ultimately comes down to choosing what’s right for your business.

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