Andreas Kretschmer

Tag:   postgresql   
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 was born in Meißen, Saxony, Germany, Planet Earth. I’m married and we have 3 wonderful daughters.

My first contact with computers was back in the GDR, a country that doesn’t exist any more. I have played with some Z80 computers at that time, programming in Machine-code and Assembler-language, a very low-level approach. It helped me to understand how that all works together. Even if I’m not a programmer nowadays I won’t forget this experience.

Since some time I’ve been enthusiastic about space travel, especially SpaceX. I like how technology changes, as example re-using rockets multiple times. That’s a great idea, like the idea behind Open Source, and, last but not least: PostgreSQL. A couple years ago, open-source databases weren’t in the same position as today. Now we are playing in the top league.

Andreas Kretschmer + SO

Andreas Kretschmer + SO

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

I don’t have any fancy hobbies. I like Mountains and interesting landscapes. For instance, a couple years ago I spent the vacation with my wife Anja and our youngest daughter Tamara in Scotland. That was very impressive. I would like to visit other regions of our world in the future.

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

I’ve been on Facebook for many years, and I’m one out of a few admins of the “PostgreSQL Server” - group there. You can find me also on Twitter, LinkedIn and XING, but not very active there.

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

Oh, that reminds me to read more. To be honest, I can’t remember my last book…

What’s still on your bucket list?

Visit more countries of the world. Visiting new places is always a nice experience. Exploring new things, meeting other people, expanding my own horizon.

What is the best advice you ever got?

Long time ago my Dad said to me: think about other people positively and always treat other people positively, unless they convince you of the opposite. I took that recommendation to heart.

When did you start using PostgreSQL, and why?

Oh, long time ago, around 2001 or 2002. I started a new job and I had got assigned the task of analysing a bunch of data. It was clear that I needed a database, and - don’t ask me why - I decided to use PostgreSQL. After some time I realised that PostgreSQL fits my requirements and that it’s a really great piece of software. I got in contact with the German PostgreSQL Community and tried to give back my knowledge to other, new members. That was the beginning ;-)

Do you remember which version of PostgreSQL you started with?

Must be around version 7.2.

Yes, I studied at the Technical University at Chemnitz (formerly Karl-Marx-Stadt, at the time I started my study). I studied information technology. I can’t say that it helps me these days in a direct way doing my job, but I would like to say completing a study will help you to stay up-to-date later in your work-life. And that’s the most important part of studying.

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

I have some MySQL knowledge, but not that much, and it isn’t my favorite product. I think you can understand that ;-)

I made my enthusiasm about PostgreSQL my daily job at 2ndQuadrant. Now I can help our customers around the globe to use PostgreSQL to solve their needs and requirements and I help them solve problems they might have. I’m also working as account manager for our customers in the DACH region.

Apart from the business side, I’m still a member of the community and help other users on a voluntary basis on several channels like Facebook, some german-speaking mailing lists and forums and also, from time to time, on one of the global PostgreSQL-related mailing lists.

Any contributions to PostgreSQL which do not involve writing code?

  • Member of PostgreSQL Europe
  • Member of the Orga-Team behind the annual PGCONF.DE conference
  • Helping other users, knowledge transfer

What is your favorite PostgreSQL extension?

BDR, developed by 2ndQuadrant. It’s not Open Source, but we have a lot of customers using it successfully. From the contrib-packages: I like pg_stat_statements a lot. Great if you have to analyse any performance issues.

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

Table bloat and Vacuum performance are things that customers are struggling with. But, you know, we have improved that in an impressive way during the last couple of versions. The MVCC model we are using is great, but it has its downsides. Not easy to ‘fix’ that at all (there is no need to ‘fix’ that, it works!, but it can be improved), but we will see improvements in the future. I’m optimistic.

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

In version 12: Generated Columns and report progress of CREATE INDEX.

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

It would be great to see the actual progress of a query. We already have the infrastructure for progress reports for VACUUM and CREATE INDEX and expanding that to any query should be the next step. On top of that, use this feature for query reporting and insights.

Could you describe your PostgreSQL development toolbox?

I don’t like GUIs, I’m using psql at work with the database. As editor I’m using vim. Please don’t start an $EDITOR war here ;-)

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

I’m not a developer, but I’m doing customer support. And from that point of view I don’t like screenshots or pictures in error reports. We need to teach our user base how to improve their error reporting, so that any one can provide better help.

Experiences with the command line and with our beautiful command-line-interface psql is a good start to get a better understanding of the database

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

In the past I have visited some of the European conferences (Paris, Stuttgart, Tallinn, Warsaw, Lisbon and Milan), all of the German conferences, Switzerland in 2017 and Austria in 2019. And yes, for some of the German speaking events I even submitted (and presented) talks!

Conferences are big community events and an opportunity to meet friends and colleagues from all around the world, learn new things and push new community ideas. Sadly this year all planned conferences are canceled because of the Corona pandemie. Let’s hope the best for next year!

Do you think Postgres has a high entry barrier?

Not really. The product follows the SQL-specification strongly, it has implemented many of the required features. We have really great documentation (well, the documentation isn’t good if you want to learn PostgreSQL, but it’s a fantastic reference to all the features we have). For beginners, we have a very helpful community, and I’m proud to be part of it!

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

Sure ;-) I wouldn’t want to work for a PostgreSQL Support Company if I wouldn’t believe in PostgreSQL. It began as a hobby and now it can support my family. Tell me one good reason to not believe in the future of PostgreSQL ;-)

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

Of course I can recommend: it is a flexible product and can support many different requirements.

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

I’m reading several lists, for instance -general and -performance, but not -hackers.

What other places do you hang out?

pgsql-de-allgemein (a mailing list), PostgreSQL Server at Facebook,, and

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

I’ve been using Linux since ages, but I’m not involved. I also like all kinds of OpenSource-Software, but PostgreSQL is the one and only project I’m involved in.

Anything else you like to add?

I think it’s impressive to see how the PostgreSQL Community is working together. Of course, there are (now) a number of companies behind the project, and we have all, more or less, the same customers, we are competitors. And we all want to earn something. But we have a strong community idea behind all of that, and we all are working together to improve our project. It’s common that people from company A find an issue and people from company B and C will help to solve this issue, there are no borders. At our annual conferences we meet and celebrate our friendship. I have the impression that this is the secret behind our success. Let’s keep it that way!