What are the Differences Between MySQL and PostgreSQL?

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If you’re looking for a database management system to use for your organization, it’s important to do your homework and make an informed decision. Two common choices for businesses are MySQL and PostgreSQL; there’s a good chance these options are already on your short list. While there’s no doubt that there are many similarities between these two databases, there are also major differences in structure, replication, SQL compliance and more. How do these two database management system stack up? In this article, we’ll do a comparison of MySQL vs PostgreSQL and look at some of the key differences between the two.

SQL Compliance

Both PostgreSQL and MySQL are SQL-compliant; however, PostgreSQL is considered largely SQL-compliant, while MySQL is only partially SQL-compliant. This may seem like a minor detail, but it matters– SQL compliance makes it much easier to migrate data from one database to another, as long as both databases are compliant.

ACID Compliance

The acronym “ACID” refers to a group of properties related to database transactions: atomicity, consistency, isolation and durability. These properties ensure valid database transactions even in the event of a failure or disruption. ACID compliance is particularly important in certain industries such as finance and healthcare. As for the two databases we’re comparing, PostgreSQL is completely ACID-compliant. MySQL is not ACID-compliant by design, but it can be considered compliant when used with certain storage engines such as InnoDB and NDB.

Open Source Licensing

There are many benefits to using open-source products– they’re freely available to everyone, they can be modified, and they tend to be on the cutting edge of innovation. PostgreSQL is an open-source, free product that is developed and maintained by the PostgreSQL Global Development Group. It’s available under the PostgreSQL License. MySQL makes its code available under the GNU General Public License, but multiple proprietary editions are also available that offer some extra functionality.


Replication refers to the process of copying data from a database on one machine or server to a database on another server. One database acts as the “master”, copying data to the “slave” databases, and the result of this process is a distributed database system. Having a distributed database is valuable for a number of reasons: It offers backup capabilities, it balances the load to optimize performance, and it allows intensive queries to run on a slave database without impacting performance on the master database. That said, both MySQL and PostgreSQL support a number of replication options.

NoSQL and JSON Support

As the need to index unstructured or loosely-structured data increases, it’s not surprising that NoSQL and JSON have grown more and more popular in the database community. PostgreSQL can support JSON, and it also supports important NoSQL features such as key-value pairs using HSTORE. With PostgreSQL, it’s also possible to index JSON, which provides speedier access. MySQL, on the other hand, is a bit more limited in its support of NoSQL and JSON, although newer versions of the product have begun offering some NoSQL support. However, it doesn’t support JSON indexing.

Community Support

Although the technical differences between MySQL and PostgreSQL are certainly relevant, don’t underestimate the importance of a strong user community. The ability to discover tips, work through problems and share knowledge with other users is invaluable. Fortunately, this is one area where both MySQL and PostgreSQL shine. Both products have active user communities and excellent commercial support. In addition, both MySQL and PostgreSQL have strong networks of contributors who work to maintain existing features and develop new ones.


Deciding between MySQL and PostgreSQL for your organization isn’t easy– both products are solid choices, and there’s a fair amount of overlap between the two. However, there are also some key differences between them, so it’s important to do your research and consider your organization’s needs before making a choice. For example, if you need an ACID-compliant database with broad NoSQL support, you might lean towards PostgreSQL. One thing is certain– no matter which of these two trusted database management systems you choose, you can hardly make a mistake.

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