Neues vom PostgreSQL Planet

Here's a database riddle: you have two tables with data connected by a foreign key. The foreign key field is set as not null and the constraint is valid and enforced. You execute a query that joins these two tables and you get no results! How is that possible? We thought it wasn't possible, but a recent incident revealed an edge case we never thought about.

In this article I show how under some circumstances row locks with joins can produce surprising results, and suggest ways to prevent it.

New podcast episode “Why it's fun to hack on Postgres performance“ with Tomas Vondra published on February 20 2026 by Claire Giordano and Aaron Wislang from the series “Talking Postgres”.

Hyderabad PostgreSQL User Group met on February 20, organized by Hari Kiran, Ameen Abbas and Rajesh Madiwale.

Speaker:

Open Source communities are trying to quickly adapt to the present rapid advances in technology. I would like to propose some clarity around something that should be common sense.

Automated emails are spam. They always have been. Openclaw (and whatever new thing surfaces this summer) is no different.

If you’ve ever run an insert statement in a terminal or an IDE, you’ve seen it: the cryptic insert 0 1 message. While it looks like a bit of ancient binary, it’s actually a precise status report from the database engine. The Anatomy of a Command Tag 🔗In PostgreSQL, every successful command returns a “Command Tag.” For an insertion, the format is: INSERT [oid] [rows] The “0” (oid1): Historically, Postgres could assign an internal Object ID to every row.

I’ve updated one of my PostgreSQL instances to PostgreSQL 18, it’s time to update the others. This time, I’m going to try pg_update. My usual approach is pg_dump and pg_restore.

As this is my first attempt doing this, I’m posting this mostly for future reference when I try this again. There will be another blog post when I try this again. Which should be soon. This paragraph will link to that post when it is available.

In this post:

A migration case with only a JAR and no source code shows why Oracle syntax compatibility is not always a fake requirement, and how IvorySQL + Pigsty can absorb legacy debt at low cost.

On 9th of February 2026, Álvaro Herrera committed patch: Allow log_min_messages to be set per process type   Change log_min_messages from being a single element to a comma-separated list of type:level elements, with 'type' representing a process type, and 'level' being a log level to use for that type of process. The list must also … Continue reading "Waiting for PostgreSQL 19 – Allow log_min_messages to be set per process type"

On 3rd of February 2026, Fujii Masao committed patch: psql: Add %i prompt escape to indicate hot standby status.   This commit introduces a new prompt escape %i for psql, which shows whether the connected server is operating in hot standby mode. It expands to standby if the server reports in_hot_standby = on, and primary … Continue reading "Waiting for PostgreSQL 19 – psql: Add %i prompt escape to indicate hot standby status."

Jeremy Schneider suggested a change to how plans are displayed – adding another bit of information in case we have timing information for IO for explain node. Took me a while to research, but it finally made it's way… Let's consider this simple plan. In it's Parallel Seq Scan node we see: -> Parallel Seq … Continue reading "Per-worker, and global, IO bandwidth in explain plans"

Modern applications heavily rely on ORMs (Object-Relational Mappers) for rapid development. While ORMs accelerate development, they often generate queries that are not fully optimized for database performance. In such environments, database engineers have limited control over query structure, leaving indexing and database tuning as the primary performance optimization tools.

If you attended FOSDEM 2026, you probably noticed discussions on how AI impacts FOSS, mostly in detrimental ways. Two of the three keynotes in Janson mentioned this, and I assume other speakers mentioned the topic too. Moreover, it was a very popular topic in the “hallway track.” I myself chatted about it with multiple people, both from the Postgres community and outside of it. And the experience does not seem great …

If you read previous post about buffers, you already know PostgreSQL might not necessarily care about your rows. You might be inserting a user profile, or retrieving payment details, but all that Postgres works with are blocks of data. 8KB blocks, to be precise. You want to retrieve one tiny row? PostgreSQL hauls an entire 8,192-byte page off the disk just to give it to you. You update a single boolean flag? Same thing. The 8KB page is THE atomic unit of I/O.