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Henrietta Dombrovskaya

Henrietta Dombrovskaya

Database Architect at DRW Local organizer of Chicago PostgreSQL User Group

Henrietta Dombrovskaya is a database researcher and practitioner with over 40 years of academic and industrial experience. She holds a Ph.D. in Computer Science from the University of Saint Petersburg, Russia. At present she is

  • Database Architect at DRW Holdings in Chicago, IL
  • Local Organizer of the Chicago PostgreSQL User Group
  • Active community member, a frequent speaker at the PostgreSQL Conferences
  • A researcher focused on developing efficient interactions between applications and databases and implementation of temporal data
  • An author of PostgreSQL Query Optimization book

POSETTE 2024 Talk

Tuning Parameters in Postgres vs. Tuning Your Queries

(Livestream 1)

When it comes to database performance tuning, most PostgreSQL practitioners focus on optimizing configuration parameters. It is often assumed that as soon as we choose the correct values for parameters and restart the database instance, all the world's problems will be solved. Indeed, due to tuning the configuration parameters, we can observe that database performance increases by 10-20% and sometimes by up to 50%. That might sound like impressive numbers, but individual query optimization routinely makes queries run several times faster, sometimes ten or more times faster. All of us might recall some examples of such drastic performance improvement, but it is not easy to quantify the impact. In this talk, we will demonstrate the difference each approach can make. We will compare the impact of tuning different memory allocation parameters with the impact of creating missing indexes and, finally - with the impact of query rewrite. Hopefully, the numbers will speak for themselves.

Speaker Interview

About the Speaker

  • Tell us about yourself: career, family, passions

    I was first exposed to the amazing world of data and databases as a sophomore at the University of Saint-Petersburg, and I immediately thought that that was something I wanted to do for the rest of my life. Forty-two years later, I am still in love with databases and still do all things data management-related. My husband and my daughter share my love and fascination with the world of data, while my two sons chose completely different careers. It is too early to say what careers my two granddaughters will choose, but who knows?

    In addition to being busy at work approximately 200% of the time, being a local organizer of the Chicago PostgreSQL User group, being the book author, and a frequent speaker at different conferences, I also support several non-profit organizations, both as a donor and as a volunteer. The most important for me are the Night Ministry and Illinois Choice Action

  • How do you prepare for an online presentation?

    Same way as for any other presentation: I review my slides and then rehearse them a couple of times in the presenter's mode, taking notes of the speed. Often, people do not pay attention to how long their in-person presentation is, but I always make sure I fit into a timeslot. One important thing with online records: I need to make sure my eyes are not closed half of the time! It is not so bad when you present in person, but in recording, it is unforgiving!

  • Which book are you reading right now?

    More often, I listen to audiobooks rather than read. The book I am listening to right now is "The Choice" by Edith Egert

  • What is your favorite hobby?

    • Biking, especially along the Lakefront Trail
    • Yoga
    • Working out in general
    • Art and music appreciation (in all forms)
    • Baking (did you know that I bake one thousand Christmas cookies and send them to my friends all over the world?)
    • Nature walks
    • Coffee and Chocolate!

About the Talk

  • What will your talk be about, exactly? Why this topic?

    Despite life proving it wrong, there is a persistent belief among Postgres users that the only thing you need to do to ensure your system functions perfectly is to find a magic set of values for Postgres configuration parameters. As long as you find them and apply them, all of your problems will be solved, and applications will run at the speed of light. This is not exactly how things work in real life, and during this talk, we will learn what configuration parameters can and can't do for your database.

  • What is the audience for your talk?

    Everybody who believes in the magic of parameters and those who do not believe in it but do not have enough arguments to support their case.

  • What existing knowledge should the attendee have?

    Some working knowledge of Postgres and a history of frustration with Postgres not performing as expected.

  • Which other talk at this year’s conference would you like to watch?

    That's an extremely tough question because I want to watch everything, except probably the talks which I have already watched! There may be just two or three, which I am willing to skip, but I do not want to single them out! The whole conference program is exceptionally well-curated, so the only reason I may skip some talks will be if they interfere with my job responsibilities!

  • How do you balance technical depth with engaging storytelling in your conference presentations?

    As they say, once a teacher, always a teacher, or you can say it's an "occupational disease" - I love teaching people new things, and I am reasonably successful in it, so I hope that my talk is well-balanced.

About PostgreSQL

  • What inspired you to work with PostgreSQL?

    First, it was an accident: I needed to get out of the place where I worked back then really fast, and a friend of mine referred me to Enova International for their open Postgres DBA position. The exact wording was: we know that you do not know Postgres, but that's OK; nobody knows Postgres. We know that you are a good DBA, and that's all we need. Since I needed a fast exit, I thought that I would take that position, hang out there for 3-4 months, and then look for a "real job" with Oracle. It was a shock to realize that being Postgres DBA is drastically different from being an Oracle DBA, but also, during these first three months, I felt in love with Postgres, and never looked back!

  • What is your favorite PostgreSQL feature?

    Postgres query planner - is the best-ever optimizer among both commercial and non-commercial database systems!

  • What is the single thing that you think differentiates PostgreSQL most from other databases?

    I know I am expected to reply: extensibility, but I am going to stand my case: the approach to query planning

  • What is your favorite PostgreSQL extension or tool? And why?

    Foreign Data Wrappers, all of them, the whole idea of being able to easily connect to a huge variety of different data storage systems.

  • What advice would you give to someone starting their journey with PostgreSQL?

    If that's not your first DBMS, forget everything you learned while working with other systems. If you had some Data Management classes in college, forget what you learned. Embrace a new world, and fear not. There is a largest community out there to support you.

  • What are your favorite resources for learning about PostgreSQL?

    Asking people who know more than me. Experimenting and asking again.

  • In your opinion, what are the most common pitfalls or mistakes developers make when working with PostgreSQL?

    Jimmy Angelakos wrote the whole book about it, and I think everybody who works with Postgres should read it. There are too many to list in an interview. One of the worst would be trying to "make Postgres work like Oracle."

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

    Open mind and a deep knowledge of relational theory

  • What is the most overlooked thing about PostgreSQL?

    Functions and stored procedures are severely underused and misused, especially the ability to generate SQL dynamically.

  • If you had a magic wand, what single thing would you change in PostgreSQL as it is today?

    Permissions management

About POSETTE & Events

  • Have you enjoyed previous POSETTE (formerly Citus Con) conferences, either as an attendee or as a speaker?

    I spoke at last year's event.

  • What motivated you to speak at this year’s POSETTE: An Event for Postgres?

    I was surprised to see how many people watched my last year's talk and with the amount of feedback/follow-ups I received. One of the most striking moments was when my co-worker learned about my work from Citus Con and wanted to use it! I hope for a similar resonance this year!

  • What other PostgreSQL events in 2024 are you excited about?

    I was very happy with PGDay Chicago, which I hosted, and I am very much looking forward to PGConf NYC and PGConf EU.

  • What advice would you give to fellow speakers preparing for a PostgreSQL conference?

    Rehearse, rehearse, rehearse!!!

  • What would be helpful for a first-time speaker?

    • One slide per minute. You think that there are longer slides and there are shorter slides, but they will balance. If you are giving a 25-minute talk, there should be 25 slides, including the title slide and the Q&A slide.
    • Do not make your slides crowded. Put half of what you want on each slide. Use animation to gradually display more and more content if you are convinced you need more on one slide.
    • Rehearse with somebody who has some experience presenting. Rehearse with somebody who is unfamiliar with the topic and note how much time the questions will take.

Past Talks

Implementing Temporal Features in PostgreSQL: SQL Standard and Beyond (Citus Con 2023)

The Postgres team at Microsoft is proud to be the organizer of POSETTE: An Event for Postgres (formerly Citus Con).