Alexander Sosna



Tags:   postgresql    credativ    germany    open-source    opensource    extension    pg_snakeoil    it-security   
Category:   Interviews   
Interviewed by: Andreas Scherbaum

PostgreSQL is the World’s most advanced Open Source Relational Database. The interview series “PostgreSQL Person of the Week” presents the people who make the project what it is today. Read all interviews here.

Please tell us about yourself, and where you are from.

I am from the north west of Germany near the border to the Netherlands and Belgium. My wife, my children and I live in beautiful Nettetal, the lake town on the Lower Rhine.

I work full time at the Open Source service provider credativ as a project manager. I supervise cross-team projects, do technical sales and also have the organizational lead of our database team. If time allows I also like to give PostgreSQL training or support customers as a DBA.

In addition to my work for credativ I teach IT-Security at the Niederrhein University of Applied Sciences.

Alexander Sosna

Alexander Sosna

How do you spend your free time? What are your hobbies?

Free time has been a little tight lately.
I try to get out of the (home) office and other buildings.
Preferably with my family or with my still quite young approach trying to reduce the influence of factory farming on my life, by local hunting.

If I can’t make it out, I also like to tinker in my wood workshop or electrical engineering laboratory. At the moment I’m playing with RISC-V processors and I’m working on an acoustic localization system.

Any Social Media channels of yours we should be aware of?

I’m on Twitter and plan to start a blog for ~20 years now, so have a look at sosna.de every decade or so.

Last book you read? Or a book you want to recommend to readers?

Unfortunately, I rarely get to read in my spare time. The last books were about SCRUM and the role of the Product Owner.

Any favorite movie, or show?

I’m a bit into Rick and Morty, but do not consume a lot of linear media at the moment.

How would your ideal weekend look like?

8k days long, nothing on the schedule and out in nature with good weather. ;)

What’s still on your bucket list?

Making a bucket list.

What is the best advice you ever got?

There are only two hard things in Computer Science

  • cache invalidation
  • naming things
  • off by 1 errors

When did you start using PostgreSQL, and why?

I had my first contact in database class at the College for Technology and Media Mönchengladbach around 2004 - shame on me - at that time I was more into PHP and MySQL.
I became a user and fan when I took a part-time job as an administrator at the Niederrhein University of Applied Sciences in 2006.

Do you remember which version of PostgreSQL you started with?

The first version I remember is 8.1.

Yes I studied Computer Science at the Niederrhein University of Applied Sciences.
The knowledge and experience I gained there are still important for my daily work.
Nevertheless, I do not believe that a university degree is absolutely necessary.
We also hire young open source fans directly after school and train them ourselves, some of them I would not want to miss anymore.

What other databases are you using? Which one is your favorite?

I have the good fortune to be able to make my own decisions here most of the time, so I almost always use PostgreSQL.
For embedded applications I also like SQLite.

If I find some time there are still ideas left for pg_snakeoil .

How do you contribute to PostgreSQL and are there any contributions to PostgreSQL which do not involve writing code?

There are some tools in the ecosystem that have some commits of mine, but that is not really worth mentioning.
When I find trivial to fix bugs or missing documentation where the fix is easier than a detailed bug report I choose to rather send a patch, but unfortunately I am in no means a programmer.

I see my added value for the PostgreSQL project more in passing on my passion for open source, free databases and especially PostgreSQL to others.
This happens in many ways. Every year I teach a small three-digit number of computer science and electrical engineering students, but I also advise multiple large and mid-sized companies on their IT and database strategy.
Special eye-openers here are migration projects from large commercial database management systems.

What are your favorite PostgreSQL extensions?

I have to mention pg_snakeoil, because it’s the first somewhat useful one I made.
More important for the rest of the world are pg_stat_statements which everyone should know and postgresql-unit which is really cool because it makes working with SI units super fun, have a look at it.

What is the most annoying PostgreSQL thing you can think of? And any chance to fix it?

PostgreSQL is a clear product of evolution, so especially from new users I regularly hear they would appreciate a more clean and polished feel with less but more versatile tools.
This gets more complicated if they need to run multiple versions of PostgreSQL on the same host.
Here I really appreciate Debian’s postgresql-common system, but there might still be room for improvement.

Personally I’m once in a while a bit annoyed that declarative partitioning does not work out of the box for most of my use cases and still needs manual work, but because it gets better and better with every major I have great trust in the community and look forward to what is coming.

What is the feature you like most in the latest PostgreSQL version?

The latest release at the time being is PostgreSQL 13 and I liked to see the improvements in partitioning and the deduplication in B-tree indexes.

Which skills are a must have for a PostgreSQL developer/user?

I can’t talk for the developers but for using PostgreSQL the main skill someone would need is curiosity in data and the willingness to read the really good docs.

Which PostgreSQL conferences do you visit? Do you submit talks?

You have good chances to see me at PGConf.EU and PGConf.DE , sometimes as a speaker.

Do you think Postgres has a high entry barrier?

The question is a bit open:
For users I think the barrier is quite low compared to the other RDBMS around, of course it’s a good idea to read the docs or find someone to give you a kickstart.

Do you think PostgreSQL will be here for many years in the future?

Yes. Yes it will. There is a huge pile of use cases and for many of them I don’t see a lot of serious alternatives at the moment.

Would you recommend Postgres for business, or for side projects?

Why not both?
It’s great for everything from playing around to running the core databases of a multi billion Euro insurance company.
I for sure enjoy both.

Are you reading the -hackers mailinglist? Any other list?

Shame on me, I unsubscribed -hackers some time ago but I still like to listen to my colleagues discussing the topics.

Which other Open Source projects are you involved or interested in?

I’m interested in many projects but did my last big code contribution when I was writing my master thesis.
I was working on a small autonomous vehicle and needed a quite resource efficient Linux driver to get the depth information (3d scan) out of a Microsoft Kinect sensor.
It was necessary to run the full autonomous control software stack including the driver on a small prototype vehicle which used a Raspberry Pi gen 1.
At this time there was only the proprietary Microsoft SDK which only supported Windows and the userland driver libfreenect written in Python which unfortunately could not run on the small embedded system.

So I learned how to use Wireshark for debugging USB packages and reverse engineered the proprietary protokoll.
With the gained knowledge I developed the needed driver and published it as librekinect.
It turned out that there were some other people out there having the same need and the driver found some fans.
A kernel developer took notice and it was included in the upstream kernel.

Anything else you like to add?

I am really thankful for everyone who makes it possible for me to have such a world class RDBMS at my disposal, thank you all!
And I am also quite pleased by some proprietary RDBMS vendors who are very successful in getting their customers to look at free alternatives.