The Best in Open Source Database Software: Top 10 Options

Most applications and programs in the modern era need somewhere to store data. For web applications, a database is a crucial cog in the wheel.

There are a few factors to consider when choosing a database: one primary aspect is its cost, but flexibility and support from hosting providers are also crucial. An open source database is your best choice for many reasons.

For example, an open source database will not affect your budget, nor will you have restrictions on how you can use it. Like a content management system (CMS) like WordPress, open source tools can offer immense power and functionality. Even better, some of the most popular (and supported) databases are open source solutions.

An Introduction to Open Source Database Software

A database is the backend storage for an application, such as, say, a web application (which is the main type of application we'll be talking about in this article). The database itself sits on your server, along with the other backend elements, such as your site's main files, any media you use, and the server's configuration files.

In a general sense, the database is one of the endpoints of your site. For example:

Your site's pages will use HTML and PHP to talk to the server.

The server will access the database on your behalf (a fluid process), extract or enter data and return it to the frontend.

Your site will display or update its content based on the database.

It is a critical piece of technology for your site and your server. As such, you'll want to have as much flexibility and knowledge of your database as possible.

This brings us to the first consideration: whether to opt for an open source database or a proprietary one.

An open source database will be 100% available to you in terms of code base and system potential. In contrast, a fully closed proprietary solution will not offer the same level of depth or flexibility, unless the developer chooses to enable it.

Some databases work on an "open source" basis, such as MongoDB:

However, this represents an excellent middle ground for some developers. Indeed, there are many fans of "NoSQL" databases, but those fans will still find restrictions in using an open source or closed source database. On the other hand, an open source option will be more adaptable to your needs.

How (and where) to use an open source database

It's worth noting that the type of license doesn't necessarily restrict the applications you can use it for. Still, an open source database has a few different use cases that fit the license perfectly:

WordPress: The open source core of WordPress works well with an open source database, mainly because of the lack of restrictions. This means you can create a powerful application customized for your needs, especially when working with the REST API.

Key-value storage: You will find that key-value storage is a resource-intensive task that sometimes needs the deft touch of a skilled developer to optimize it. An open source database solution will allow a developer to dig deep into the code and make those adjustments seamlessly.

Niche technologies: Many technology applications benefit from other open source tools such as databases. Artificial intelligence (AI), graphs and different niches can work with an open source database like WordPress does (without restrictions) and take advantage of the flexibility of the database itself.

Data science: Data science is another area where an open source database works well. Again, popular languages in this area, such as Python and R, work best with MySQL, MariaDB and MongoDB, but less so with proprietary solutions.

Data storage: An open source database can be more secure than a proprietary one (due to the visible code base), so it is also a good choice for privacy-centric data storage. This is reinforced when you combine the database with other privacy-centric solutions, making the setup remarkably secure and scalable at a low cost.

The theme running through all of these use cases is that an open source database offers few restrictions. Because of this, you can leverage the power of the database software and tailor it to your needs.

This brings us to why using an open source database might be good for you.

Why you'll want to use an open source database.

Of course, a database itself is an essential component of any web application. You'd be hard-pressed to create anything useful without one. However, you may not see the immediate benefits of choosing an open source database.

You'll find that you'll use an open source database for the same reasons you'd choose an open source CMS like WordPress. For example:

The information you store in the database is yours, with no compromises or restrictions.

You can build on top of the database software, just like WordPress. This opens up almost endless possibilities for what you can accomplish and offers exciting options.

An open source database is a great way to scale and drive an application and business without worrying about licensing or higher purchase costs. You can focus on making the database work for you instead of fighting licensing.

At this point, you can probably see how an open source database is an undisputed winner over proprietary or even source code solutions. With that in mind, let's dive into some of the best options on the market.

The Best in Open Source Database Software: 10 Examples

The following list contains some open source databases, but it is not exhaustive. There are many more options than we could include here, so we have selected our top choices.

Our first entry is possibly the most prominent option for an open source database, so let's start there.

1. MySQL

If you take a minute to look at databases for applications, MySQL will top many lists. The same is true here because it was a default choice for many developers for a long time.

Oracle developed it as a relational database management system (RDMS). This means that it will use tables to store data, and that those stored data types might be linked in some way.

The core of MySQL was to take an older (though popular) proprietary database system, keep most of the compatibility, and make the result open source. Because developers can move to it without having to relearn MySQL, it has been a staple of application development for decades.

Much of the functionality you'll find in many databases mirrors or derives from MySQL. For example, you'll use Structured Query Language (SQL) to work with the database relationally, and you'll use almost any programming language to connect to the database itself.

You don't need to know much about SQL to use MySQL, and the learning curve is not steep. You can work with the database from the command line, and MySQL has great compatibility with almost any operating system (OS) you will use.

In general, MySQL is ideal for most use cases, as it is a robust, fast and reliable tool. Because of this and its positioning relative to other solutions over the years, most hosts support MySQL databases. However, there are also some drawbacks to consider:
  • Although MySQL is efficient in most cases, it can be slower for large databases.
  • Also, its debugging tools could be improved compared to other (even proprietary) solutions.
  • There are cases of data corruption, although it is not a serious problem.
It is difficult to name too many negative aspects because, in general, MySQL is a solid and reliable database that fits most applications. However, some users look for other products for the reasons we will see below.

2. MariaDB

Although Oracle owns MySQL at the time of this writing and continues to offer it as an open source solution, its reputation is not that of an open source advocate. At the time of the acquisition, one of the founders forked MySQL to create MariaDB:

Since it is a fork of MySQL, compatibility is almost 1:1. MariaDB developers also like to keep compatibility close to their fork. Therefore, you can use MariaDB as a MySQL replacement with little consequence and migrate to it without any problems.

Although MariaDB is a fork of MySQL, it is still looking to forge its own path. There are some unique features of the open source database that you should know about:
  • MariaDB uses the Aria storage engine to handle complex SQL queries. This gives the database a speed boost over MySQL.
  • You can use dynamic rows for table columns, which promotes flexibility and adaptability.
  • There are some specialized storage engines for specific use cases that you won't find in MySQL. For example, you can implement distributed storage, distributed transactions and more.
Because of the tight compatibility, you can use MariaDB wherever you use MySQL without many restrictions. Therefore, you can consider it "all things to all applications", just like its fork. However, keep in mind that compatibility is only one way, so you'll have to choose sides: MySQL or MariaDB. This open source database commands loyalty!

3. PostgreSQL

If all you know is PHP and WordPress, you probably don't know much about PostgreSQL. However, it's an open source relational database that many developers use in the data science, graph and AI industries because it's ideal for Python and Ruby applications (although you could also use PHP).

Compared to the robust denim of MySQL, PostgreSQL is more like fine silk in the sense that it is a thoughtful, open source database that offers many impressive features:
  • You can implement asynchronous replication.
  • It has native support for JSON-style document storage, key-value storage and XML.
  • You can perform full-text searches on your database.
  • Several built-in data types will be very valuable for some applications, such as geolocation, arrays and ranges.
Still, you will need to handle PostgreSQL with care, as it is not as adept as other solutions for read-intensive applications. For one thing, if you have to create reports from existing data on a regular basis, PostgreSQL's document storage could suffer with such a large data set.

However, this same document storage model is ideal if you want to include NoSQL-style functionality in a hybrid fashion. Native support for key and document storage is a time saver that allows you to move quickly through a project.

4. Redis

Redis is different from the rest of the open source databases on this list in that it is not used for almost any of the same applications.

It is a database that allows you to structure data as key-value pairs. It is similar to associative arrays in PHP or dictionaries in Python: it is a way to link data for quick reference later:

"Speed" is the crucial term here because Redis is a database that is used for caching. There are a few reasons for this:
  • Redis is an "in-memory" storage solution - entirely in RAM - which means that read and write speeds are lightning fast.
  • You can learn the basics of Redis in a few minutes and start storing objects right away.
  • You can set expiration times for strings, which is a critical component of caching.
  • A novel Pub/Sub feature uses Redis as a buffer for messages between a sender and receiver. Instead of these endpoints establishing a direct connection, the sender will send a message to a dedicated Redis "channel," which then moves it to the receiver (and vice versa).
All this means that Redis is great for distributed data and for implementing caching. It won't be the best for more complex applications, but this is not within its remit. Instead, you'll use it alongside another database, such as MariaDB, to support the rest of your application.

5. SQLite

In the case of this open source relational database, the clue to the key selling point is in the name: SQLite is a tiny, lightweight library that offers a database engine.

You will often find it on smaller devices, such as smartphones, because it is lightweight. In fact, the entire database consists of a .sqlite file that can live anywhere on your system. You won't need to install any server software or connect to other services to use SQLite.

Despite the database being such a lightweight tool, you can have a database size of hundreds of terabytes, with a maximum row size of one gigabyte. Even with file sizes that large, SQLite is still fast.

You will find that there are many good use cases for using SQLite as a database:
  • Developers of simple applications will like SQLite because it's a straightforward, uncomplicated solution.
  • It's ideal for Internet of Things (IoT) applications where there won't (or can't) be a sysadmin or developer on hand.
  • SQLite may be suitable for low-traffic websites, because those needs will be straightforward.
  • Although we are primarily talking about web applications here, desktop applications could also use SQLite to maintain high performance.
Given the structure of SQLite, it is not going to work as well for high-traffic sites, as performance will not be optimal. Also, this lighter weight open source database lacks some features that might be important. For example, you can't query the database with a client like MySQL or MariaDB.

6. Neo4j

Most of the open source databases on this list are relational. For a change, Neo4j is graph-based.

This is great for some of the most modern web applications you will find. Neo4j is just about the only solution you'll find for implementing a graph-based database (so far).

Data doesn't usually arrive in an ordered array of tables, rows and columns. We order them this way through relational databases. However, it is difficult to reproduce organic connectivity via SQL for modern web applications, such as social networks. It is unstructured, which makes it the opposite of SQL.

Therefore, Neo4j is a single database for almost any application you can handle, and it offers many advantages:
  • It's fantastic for turning tabular data into graphs and supporting the resulting analytics.
  • Neo4j is also stellar for transactional applications.
  • It has a dedicated query language (Cypher) to help you get to the data and work with it optimally.
However, performance can be an issue, due to how the database is structured. For example, you can only use "hash indexes" to sort the data, unlike the range indexes of other solutions. This can tax your system resources and affect performance.

However, if you want to implement a graph-based database, Neo4j can meet your needs. It is a top-notch open source database, as long as you use it as intended.

7. OrientDB

We said there were "almost" no other open source graph-based databases, but that leaves room for others. OrientDB is one of them. Although it has changed ownership over the years, it is still a great way to implement a graph-based database for your web application.

OrientDB can address various models, such as objects, graphs, documents and key values. Still, it is classified as a NoSQL solution, and there are direct connections to records, so its core is like a graph-based database.

The main advantage of OrientDB is its flexibility and scalability. Like Neo4j, it is fast, but it comes with performance caveats. However, OrientDB is more flexible and is developing other indexing mechanisms to help users.

You will find that OrientDB is as capable as Neo4j in the same range of applications, e.g., social networking, banking and finance, traffic management, etc.

8. CouchDB

Apache - the server type - also develops CouchDB. Like SQLite, it is a small, unobtrusive open source database that is a working solution for countless projects.

The goal of this open source database is reliability. The idea is that the data is in a cluster of multiple distributed nodes. Some of these nodes will be offline, and will "hold" the data until they come back online. Then, all the data is fed into the cluster and distributed to the other nodes in the network.

To explain further, imagine a database containing data generated on a mobile device. There is no guarantee that this device will access an online connection, so the data will remain there until its "node" comes back online.

Therefore, CouchDB is a resilient and reliable database that should be a key consideration if you need offline tolerance.

That said, the most significant positive aspect of CouchDB is also its downside. You have to store redundant copies of data, which will bloat file sizes. Also, you will find that the write speed is not fast, so it is not suitable for use cases that demand fast response.

However, being an open source database designed for reliability, CouchDB is the best choice for law-abiding applications.

9. FirebirdSQL

FirebirdSQL is not as well known as other databases on this list, but it can serve a vital function in certain scenarios.

You will see that FirebirdSQL has almost all the same features and functionality as other SQL-based databases, and offers full compatibility with MySQL. That's probably why you won't find many advocates of the database: there are too many similarities with other platforms. However, it can stand on its own in several respects:

It offers a small footprint, which is handy when space is at a premium.

You can use FirebirdSQL as a database for a desktop application that needs to scale, such as LibreOffice.

The database is cross-platform and has low hardware requirements. This makes it a solid solution when you need to run large databases.

There are also high-profile users of FirebirdSQL, such as National Rail in the UK. Despite the prevalence of other solutions, FirebirdSQL could work as a lightweight but powerful open source database for your project.

10. BigchainDB

We'll give you one guess as to which industry and application BigchainDB seems to excel in. This open source solution takes a distributed database and incorporates blockchain technology to enhance the experience.

Like the key elements of blockchain, BigchainDB uses immutability, decentralization and "multi-assets" to help you manage your data.

You can customize your network based on rich permission settings, custom assets and more. The database can also work with decentralized configurations, although security or privacy-focused applications offer the best use cases.

For example, you'll find it's a great ally for preserving intellectual property (IP) rights and verifying user credentials. Conversely, you will find that BigchainDB is not suited to most typical applications and may in fact be overkill for many web applications.

Like Neo4j or OrientDB, if you have a strict use case and need BigchainDB, you'll be happy. It can add a lot of unique facets to your privacy-centric web application, so it could work alongside your core open source database to enhance your performance.


If you want to create an application of any kind, you need a database. Web applications need at least one database, and you may need several to contain all the data you process in various use cases.

Although there are many databases with different license types, an open source database is going to be your best choice for most cases.

Like open source solutions like WordPress, an open source database will offer you flexibility, scalability and security at a basic level. Even better, tools like MySQL, MariaDB, PostgreSQL and Redis are all open source, popular and supported by many web hosts.