Where do performance cliffs come from?

Join us for an evening of great tech discussions, networking, and of course—free pizza! After we dive into the fascinating world of Postgres performance cliffs, grab a slice, meet fellow PostgreSQL enthusiasts, and connect with the M-PUG community.

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When running queries on a Postgres database, chances are you have
experience with hitting a "performance cliff" - an abrupt change of
performance for a given Postgres query, after only a small change in
data and/or query parameters.

In this talk, you'll learn why performance cliffs happen in Postgres.
After a brief explanation of how cost-based optimizers work and what
assumptions that relies on, I'll show a couple examples why/how it
fails. I'll also share recommendations on how to mitigate these issues.

If time permits, I'll talk about a couple interesting improvements &
possible solutions proposed in recent research projects, focused on
making Postgres query execution more adaptive & robust.

### Speaker:

Tomas Vondra - first met Postgres in 2003 and quickly became a big fan. He helped to port various applications to Postgres from other databases, managing Postgres instances, tuning and fixing performance issues etc. He is also a member of the executive committee of CSPUG (Czech and Slovak PostgreSQL Users Group), an "umbrella" organization for the local PostgreSQL community. Tomas currently works as a database engineer at Microsoft, working on various PostgreSQL-related tasks, open-source contributions etc.

Please also RSVP here: https://foocafe.org/event/where-do-performance-cliffs-come

### Agenda
17:30 – 17:45 – Meet & Greet
17:45 – 18:30 – Presentation
18:30 – 19:00 – Meet & eat
19:00 – 20:00 – Q&A