PostgreSQL Query Latency & Transaction Isolation

We're excited to be back for our 4th event of 2025 and pleased to say this event is being supported by Cockroach Labs.

The event will be taking a look at measuring query latency the hard way and a practical story of serializable isolation.

Main Talk: Measuring query latency the hard way: an adventure in impractical Postgres monitoring
By: Simon Notley - EDB

Sampling the session state (as exposed by pg_stat_activity) is a
surprisingly powerful way to understand how your Postgres instance
spends its time. It something I can whole-heartedly recommend to any
Postgres DBA that needs a lightweight way to monitor query performance
in production. However it's a terrible way to measure query latency,
fraught with complexity and weird statistical biases that could be
avoided by simply using an extension built for the job, or even log
analysis. But pursuing terrible ideas can be fun, so in this talk I
dive into my adventures in measuring query latency from session
sampling, generate some *extremely* funky charts, and end up
unexpectedly performing a vector similarity search.

Short Talk: Serializable Isolation - Why you should get there and How we did it
By: Matthew Gardner - Cockroach Labs

Explore why Serializable isolation is an important foundation for correctness in databases and how we navigated the practical journey of migrating an existing workload there. We'll talk about how to debug and resolve contention in high-concurrency workloads, and practical techniques like query refactoring, review EXPLAIN plan and tuning strategies that make strong guarantees achievable based upon production experience.

On The Evening

We have a pre-paid bar tab open (first come first served), so come in grab a drink of your choice at the bar and join us in the upstairs room.

We'll have a short introduction to the meet up, before kicking off with Measuring query latency the hard way: an adventure in impractical Postgres monitoring.

Following our first talk, snacks will arrive, and we'll have time for a Q&A with Simon and a short break.

Before moving on to: Serializable Isolation - Why you should get there and How we did it

We'll have time for a Q&A with Matthew and the chance for all to meet others and chat about PostgreSQL.

With Thanks
Cockroach Labs - For supporting the venue, food & drinks.