Mladen Marinović

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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 was born in Pula, a small city on the Croatian coast (~50K inhabitants) and I am 41 years old. My first computer was a 386 DX 40MHz and it marked the start of the road to an IT career. After high school I went to the Faculty of Electrical Engineering and Computing in Zagreb where I got a degree in Computer Science. At that time I also got a degree in psychology. During my years at the university in Zagreb I volunteered at KSET, a student club for Electrical Engineering and Computing students, but also a great place where you can listen to really good music and engage in all sorts of extracurricular activities. After a few years of working in Zagreb I moved back to Pula, and I now work remotely as a CTO of Smartivo, a vehicle tracking and fleet management company. I also do consulting on all sorts of projects, mainly focused on data collection and processing.

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

Being so busy on different projects it can be hard to find free time, but I try my best. I like spending time with my wife and daughter, walking our dog and going on hikes. When my daughter turned 2 I bought her a LEGO set and we have enjoyed building together since then. We also play video games together, but just newer stuff as she does not like the old MSDOS games from my youth. A couple of years ago, after a moderate knee injury, I started running, just to have another excuse not to be in front of a computer screen. It turns out I am good at it and I will probably try to run an entire marathon at least once in my lifetime.

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

I have a blog but it has been a long time since I wrote anything. It started as a way to vent after work, but it became just another side project that you should do regularly. My Twitter and LinkedIn profiles are a bit more active, but not much.

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

Besides a bunch of children’s books and the entire HarryPotter series, I don’t remember which book I read last if it was not work related.

Any favorite movie, or show?

I like to watch Futurama, when it is not canceled, Lego Ninjago and the Big Bang Theory.

What does your ideal weekend look like?

It would probably start without an alarm set to go off and continue with my phone battery dying early in the morning. After that, any social activity with my family, at home or outside in nature, is more than enough to call it an ideal weekend.

What’s still on your bucket list?

I don’t mantain a list of that sort because I would be constantly adding more stuff. I would like to travel to new places a bit more, but COVID got in the way of that.

What is the best advice you ever got?

When my wife gave birth to our daughter and they were still in the hospital, a friend of mine told me to sleep now because it will be the last sleep in the following years. I pass it on to all my “soon to be father” friends.

How and why did you start using PostgreSQL?

The first version I used was 8.0 in 2005. A friend of mine recommended using PostgreSQL instead of MySQL because it follows the SQL standard better than the others. After MySQL, Informix and MS SQL, PostgreSQL did feel a lot easier to set up and use. And it worked really well for the projects I worked on. I afterwards used the 7.4 version on production of a different project and I think that is the lowest version I had ever used.

Have you studied at a university? If yes, was it related to computers? Did your study help you with your current job?

I studied at the Faculty of Electrical Engineering and Computing in Zagreb where I got my CS degree. We had a couple of courses on databases and the knowledge acquired there still comes in handy to this day.

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

I have used a lot of databases (starting from MS Access, MS SQL, MySQL, MariaDB, IBM DB2, Oracle, SQLite) but PostgreSQL remains my favorite.

How do you contribute to PostgreSQL?

I am sad to say I don’t use my programming skills to improve the PostgreSQL landscape. I wrote a couple of internal scripts for wrapping certain rough edges of the CLI tools, but they are not remotely ready to be made available to the general public.

Any contributions to PostgreSQL which do not involve writing code?

Until COVID started I was very active on conferences (PGDay.IT, PGConf.EU) giving presentations (optimizations, data migrations, GDPR compliance etc.) and training on optimizing queries. I am looking forward to the conferences to start again.

What is your favorite PostgreSQL extension?

I don’t use extensions often, but I can vouch for pglogical. It saved us a lot of work when migrating data from 9.4/9.6 to 11.

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

There are a few things that come to mind. The first would probably be better tooling with GUIs for backup, replication and partitioning. A lot of work has to be done manually in configuration files and when these are “one of a kind” instances a GUI would be better suited for the job.

The CLI tools that come with PostgreSQL can also be problematic. I know that all I have used don’t have custom hooks you can supply for extending the functionality (pg_receivewal - a hook when a WAL segment is done, or pg_rewind when a needed WAL file is missing)

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

I think the multi ranges in 14 will be the most used part for me. Also the MERGE in the 15 release.

Adding to that, what feature/mechanism would you like to see in PostgreSQL? And why?

A dynamic multimaster would be a dream come true for almost all projects I have been working on the last 10 years. Being able to not care which server is primary and to add additional servers when space/performance runs low would make life easier for a lot of people.

Could you describe your PostgreSQL development toolbox?

We use PyCharm for development and the DB extension works really well. On other projects we write the queries in pgAdmin(3/4).

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

Knowing SQL should be skill no. 1. A little bit of theory on sets, sorting and indexing will greatly improve understanding how databases work and make developers/users write better queries.

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

I usually go to PGDay.IT and PGConf.EU. I try to submit talks every year.

Do you think PostgreSQL has a high entry barrier?

No. I think it is easy to install and use with default settings. Have you ever tried using Oracle? Jokes aside, PostgreSQL is great, but it could be better. More entry level tutorials and documentation would lower the barrier even more, and that is something almost everyone in the community can contribute.

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

It has been here for long and it seems it will be here for at least that much.

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

I use it for both, and it never lets me down. If there are problems, 99.9% of the time it is not PostgreSQL.

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

I tried following the -general mailing list and it was too much. I read the lists when I have a problem I can’t solve by myself and I can just say that everyone there is very helpful. Especially the elders :)