`scram_iterations` embeds itself in each password when set and stays there forever, making it a per-password property masquerading as a server setting.

`row_security = off` doesn't disable row-level security—it triggers an error when a policy would apply.

PostgreSQL 16.4, 15.8, 14.13, 13.16 and 12.20 added a security parameter that only pg_dump uses.

PostgreSQL's `restore_command` asks for WAL segments one at a time until the command fails—and that failure marks the archive's end, whether it's real or not.

When a PostgreSQL backend crashes, the postmaster can restart itself automatically or exit and wait for external intervention.

PostgreSQL 16's `reserved_connections` reserves slots for your monitoring and backup roles when the application exhausts the pool.

Protect your disk from orphaned temporary files after a backend crash.

PostgreSQL 15's `recursive_worktable_factor` helps you fix slow recursive CTEs by tuning a single estimate.

Restore to the moment before the disaster using eight parameters that answer where replay stops, which timeline to follow, and what to do when you get there.

Create replicas with a single command, but master the procedure for replacing a failed primary—that's where things get tricky and installations break.