MariaDB: story of a MySQL fork

MariaDB was born as a fork of MySQL that means they share the same code up to a certain point, that point was MySQL v5.1 (29 Sep 2009). The community decided to fork MySQL due to concernsabout the Oracle acquisition and what MySQL would become.

Oracle was mainly a software company and most of its core business was at the time, well, databasesOracle Database is the Oracle’s main product and it is often regarded as the standard database for the enterprise. With the acquisition of MySQL, the community feared that Oracle would limit the growth of what used to be a complete open source DBMS. The day Oracle announced the acquisition of Sun, Ulf Michael Widenius, the main author of MySQL, announced the fork of MySQL and the birth of MariaDB. The cofounder of MySQL took a handful of MySQl developers with him.

Oracle has since created derived products: MySQL Community Editions (the “original”, open source) and MySQL Standard, Enterprise editions that include closed source software and Oracle support.

A drop-in replacement

The main selling point of the newly born DBMS (Data Base Management System) was to keep compatibility with MySQL and to be a drop-in replacement for it.

Drop-in replacement means that a software using either won’t notice if you switch between the two and will continue working without any problem. This was done in order to provide users with an easy way to switch to the new software without disrupting their activities.

Maintaining MariaDB as a drop-in replacement was a right call to allow users to switch in the short period, but it would’ve been a double-edged sword in the long run: MariaDB would’ve had to implement every single change implemented by Oracle, and that would’ve defeated the original reason behind the fork. That’s why not all versions of MariaDB are compatible with MySQL (more in a while).

MariaDB, MySQL: storage engines

First and foremost MariaDB released Aria, a storage engine to replace the older, but still widely used, MyISAM. For a short while MariaDB used XtraDB (a storage engine from Percona) as default, to later return to InnoDB. It may not seem like a great feat now, but at the time MyISAM, the default MySQL storage engine, would employ table-wide locks that resulted in poor performance and query stacking.

In time MariaDB’s InnoDB, the current default engine, diverged substantially from MySQL’s InnoDB, leading to incompatibilities, up to the point that no version of MariaDB can be used as drop-in replacement for MySQL 8.

At the moment MariaDB supports the following engines:

  • InnoDB (since version MariaDB 10.3 it has diverged substantially from MySQL’s implementation)
  • XtraDB
  • Aria
  • MyISAM
  • ColumnStore
  • TokuDB
  • MyRocks
  • follow this link for a full list.

While MySQL supports:

  • InnoDB
  • MyISAM
  • Memory
  • CSV
  • Archive
  • Blackhole
  • NDB
  • Merge
  • Federated
  • Example

Notice that Memory, CSV, Archive, Blackhole, Merge, Federated, Example are also available in MariaDB.

Central PA Open Source Conference

The Central Pennsylvania Open Source Conference (CPOSC) is a one-day technical conference for open source users and developers. Presentations and sessions cover all aspects of open source, with talks ranging from novice to expert skill levels and featuring case studies, best practices, code-alongs and more. Join us for a day of meeting with and learning from your technology peers.

Hey there,

I’ll never forget launching my first open-source project and sharing it on Reddit…

I had spent a couple of days at my parents’ place over Christmas that year and decided to use some of my spare time to work on a Python library I christened Schedule.

The idea behind Schedule was very simple and had a narrow focus (I find that that that’s always a good idea for libraries by the way):

Developers would use it like a timer to periodically call a function inside their Python programs.

The kicker was that Schedule used a funky “natural sounding” syntax to specify the timer interval. For example, if you wanted to run a function every 10 minutes you’d do this:


Or, if you wanted to run a particular task every day at 10:30 in the morning, you’d do this:


Because I was so frustrated with Cron’s syntax I thought this approach was really cool. And so I decided this would be the first Python module I’d release as open-source.

I cleaned up the code and spent some time coming up with a nice README file—because that’s really the first thing that your potential users will see when they check out your library.

Once I had my module available on PyPI and the source code on GitHub I decided to call some attention to the project. The same night I posted a link to the repository to Reddit and a couple of other sites.

I still remember that I had shaky hands when I clicked the “submit” button…

It’s scary to put your work out there for the whole world to judge! Also, I didn’t know what to expect.

Would people call me stupid for writing a “simple” library like that?

Would they think my code wasn’t good enough?

Would they find all kinds of bugs and publicly shame me for them? I felt almost a physical sense of dread about pushing the “submit” button on Reddit that night!

The next morning I woke up and immediately checked my email. Were there any comments? Yes, about twenty or so!

I started reading through all of them, faster and faster—

And of course my still frightful mind immediately zoomed in on the negative ones, like

“Cool idea, but not particularly useful”,


“The documentation is not enough”,


“Not a big fan of the pseudo-english syntax. Way too clever and gimmicky.”

At this point I was starting to feel a *little* discouraged… This was just something I wrote in a couple of hours and gave away for free!

The comment that really made my stomach churn was one from a particularly well known member of the Python community:

“And another library with global state 🙁 … Such an API should not even exist. It sets a bad example.”

Ouch, that hurt. I really looked up to that person and had used some of their libraries in other projects…

It was almost like my worst fears were now playing out in front of me!

I’d never be able to get another job as a Python developer after this…

At the time I didn’t see the positive and supportive comments in that discussion thread. I didn’t see the almost 70 upvotes. I didn’t see the valuable lessons hidden in the seemingly rude comments. I dwelled on the negative and felt terrible and depressed that whole day.

So how do you think this story ends?

Did I delete the Schedule repo, switched careers and never looked at Reddit again?


Schedule now has almost 3,000 stars on GitHub and is among the top 70 Python repositories (out of more than 215,000). When PyPI’s download statistics were still working I saw that it got several thousand downloads per month. I get emails every week from people asking questions about it or thanking me for writing it…

Isn’t that crazy!? How’s that possible after all of these disheartening comments?

My answer is “I don’t know”—and I also don’t think that Schedule is a particularly great library that deserves all this attention, by the way.

But, it seems to solve a problem for some people. It also seems to have a polarizing effect on developers who see it—some love it, some hate it.

Today I’m glad I shipped Schedule that night.

Glad because it was helpful to so many people over the years and glad because it helped me develop a thicker skin when it comes to sharing and launching things publicly.

I’m writing you this meandering email because not very long ago I found this comment buried in my Reddit message history:


As someone who has posted a number of projects and blog posts in r/Python, just wanted to drop you a line and encourage that you don’t let the comments in your thread get you down. You see all those upvotes? Those are people that like your library, but don’t really have a comment to make in the thread proper. My biggest issue with /r/Python is that it tends towards cynicism and sometimes cruelty rather than encouragement and constructive criticism.

Keep up the great work,



Wow! What a positive and encouraging comment!

Back when I felt discouraged by all of these negative comments I must’ve missed it. But reading it a few years later made me re-live that whole situation and it showed me how much I’d grown as a developer and as a person in the meantime.

If you find yourself in a similar situation, maybe feeling bogged down by the developer community who can be unfiltered and pretty rude sometimes, don’t get discouraged.

Even if some people don’t like what you did there can be thousands who love your work.

It’s a big pond, and sometimes the best ideas are polarizing.

The only way to find out is to ship, ship, ship.

Happy Pythoning!

— Dan Bader (