Tables Store Rows. So What’s Actually Inside a PostgreSQL Index?
You probably have a clear picture of a table: rows of data, one after another. A books table holds books. A users table holds…
How to Get a Table’s DDL in PostgreSQL
Sooner or later you need the CREATE TABLE statement for a table that already exists. Maybe you want to copy it to…
How to Check If a Table Has an Index in PostgreSQL
A query that took 5 milliseconds last month now takes 5 seconds. Nine times out of ten, the first question…
How to Check If a Table Has a Primary Key in PostgreSQL
A table without a primary key can look perfectly normal. Queries run, and data goes in and out. Then one…
How to Check When a Table Was Created in PostgreSQL
Short answer: PostgreSQL doesn’t record when a table was created. No system catalog has a created_at column, and nothing in pg_class or pg_stat_user_tables stores it. That surprises a…
How to Safely Change a Role Password in PostgreSQL
You can change a PostgreSQL password with one SQL statement. The part people get wrong is how they type it. Done the…
How to Change the Hostname in Ubuntu Linux
You can change an Ubuntu hostname with a single command. There are two things to watch for: /etc/hosts still points to the…
The Complete pglogical Troubleshooting Guide: Architecture, Methodology, and Fixes
When pglogical stops replicating, the symptoms are often deceptively vague: rows stop appearing on the subscriber, disk space on the provider rapidly…
How to Disable cloud-init on Linux: 4 Safe Methods
Four ways to turn it off, one way to turn it down, and the trap that locks people out. You…
cloud-init Troubleshooting: 5 Silent Problems Hiding in Your Cloud VMs
Part 5 of “cloud-init Under the Hood”: ghost logs, lost seconds, and a password hiding in plain sight. You probably…