All Your GUCs in a Row: random_page_cost and seq_page_cost
The planner charges `random_page_cost` per index page based on how uncorrelated the index is—but the name lies.
All Your GUCs in a Row: quote_all_identifiers
Dumping across major versions? A reserved keyword can silently break constraints and policies.
All Your GUCs in a Row: primary_slot_name
Configure a replication slot name on your standby and the upstream keeps WAL forever—until the slot itself fills your disk or the standby dies holding an old…
A Parade of Horribles, in Serial Order
Sooner or later, someone on the team reads about write skew. It is an unsettling read: two transactions, each correct on its own, each looking at data the other
All Your GUCs in a Row: primary_conninfo
`primary_conninfo` tells a standby where to stream WAL from—but only after the archive and pg_wal run dry.
All Your GUCs in a Row: post_auth_delay and pre_auth_delay
Debugging PostgreSQL connections requires stopping a backend before it does anything interesting.
All Your GUCs in a Row: port
The `port` parameter does double duty: it names the TCP socket and the Unix socket file too.
The Patch Is Coming From Inside the House
On August 25, Robert Haas opened a pgsql-hackers thread like this:
All Your GUCs in a Row: plan_cache_mode
Override PostgreSQL's prepared statement plan choice when its cost estimates go wrong on skewed data.
All Your GUCs in a Row: password_encryption
What `password_encryption` actually controls: how PostgreSQL hashes new passwords when you hand it clear text.