When most people think about PostgreSQL internals, they picture tables, indexes, and perhaps the VACUUM process. Tucked away in the contrib extensions, however, is a tool that exposes what really sits on disk: the pg_visibility extension. By querying it, you see how PostgreSQL tracks visibility and freezing at the page level—information that directly affects vacuum efficiency and index-only scans.
Author: Ian Parker
Unlocking psql: Meta-Commands that Supercharge Your PostgreSQL CLI Work
If you manage PostgreSQL from a terminal you already know psql, the interactive client that ships with every installation. Most developers use it for the basics—running SELECT statements, loading a .sql file, maybe poking around with \dt to see which tables exist. Beneath that familiar surface, though, psql hides a rich toolbox of meta-commands. These commands, all prefixed with a backslash, live inside the client. They’re not SQL, they’re shortcuts built into psql itself, and they can make everyday tasks faster and far less error-prone.