allow_alter_system
We begin at allow_alter_system, which is both new and politically fraught — so let’s start with a fight.
ALTER SYSTEM was added in 9.4 as a quality-of-life improvement: set GUCs from an SQL prompt, have the values written into postgresql.auto.conf, no shell access required. It was immediately controversial among people running PostgreSQL under configuration management. If Ansible
For most of PostgreSQL’s history, the official community position on query hints has been a polite version of “no, and stop asking.”
The position isn’t subtle. The PostgreSQL wiki maintains a page titled Not Worth Doing, and “Oracle-style optimizer hints” is listed there, right above in-process embedded mode and obfuscated function source. The companion wiki page, OptimizerHintsDiscussion,
pg_plan_advice is expected to land in PostgreSQL 19. That makes this a good moment to look at query hints — what they are, what every other major database does with them, and how PostgreSQL ended up being the obvious outlier. Three parts. This is the first.
I subscribe to Medium (don’t judge), and their weekly summary pushed an article to me entitled The Postgres Revolution Is Here: Why Version 18 Changes Everything for Developers. Well, OK, that sounds relevant to my interests. Let’s check it out!
Oh.
Oh, dear.
Oh, sweet Mother of God.
Sometimes, we run into a client who has port 5432 exposed to the public Internet, usually as a convenience measure to allow remote applications to access the database without having to go through an intermediate server appllication.
Do not do this.
This report of a “security issue” in PostgreSQL is alarmist, because it’s a basic brute-force attack
PostgreSQL version 12 introduced a new option on the VACUUM command, INDEX_CLEANUP. You should (almost) never use it.
First, a quick review of how vacuuming works on PostgreSQL. The primary task of vacuuming is to find dead tuples (tuples that still exist on disk but can’t ever be visible to any transaction anymore), and reclaim them as free
I am putting this here to remind myself that unless you actively delete them, .pyc files from .py files that no longer exist can hang out and cause all kinds of weird and exciting problems, and part of your deploys should be to delete all .pyc files.
We’ve gone through a lot of detail about locales and collations here, but what should you do when it is time to set up a database? Here is a cookbook with some common scenarios, with recommendations.
In previous installments in this series about locales and collations in PostgreSQL, we’ve made some vague allusions to the speed of the various collation functions. Let’s be a bit more analytical now.
The data here was gathered on a 4GB Linode instance running Ubuntu 24.04 and PostgreSQL 17.1. The test data was 1,000,000 records, each one a string of
In this installment of our series on locales and PostgreSQL, we’ll talk about what can happen with the library that provides locales changes out from under a PostgreSQL database. It’s not pretty.
Back in an earlier installment, we described a collation as a function that takes two strings, and returns if the strings